Annual report pursuant to Section 13 and 15(d)

Subsequent Events (Details)

v3.20.4
Subsequent Events (Details)
$ / shares in Units, $ in Millions
 12 Months Ended
Feb. 04, 2021
USD ($)
manager
pipelineSystem
mile
shares
Feb. 02, 2021
$ / shares
Dec. 31, 2020
USD ($)
$ / shares
Dec. 31, 2019
$ / shares
Dec. 31, 2018
$ / shares
Subsequent Event [Line Items]          
Dividends declared per share (in dollars per share) | $ / shares     $ 0.900 $ 3.000 $ 3.000
Crimson Midstream Holdings, LLC          
Subsequent Event [Line Items]          
Due diligence and transaction related costs | $     $ 1.5    
Series A Preferred Stock          
Subsequent Event [Line Items]          
Coupon rate percentage     7.375% 7.375%  
Depositary Shares          
Subsequent Event [Line Items]          
Percent equivalent of preferred shares     1.00%    
Preferred Stock | Series A Preferred Stock          
Subsequent Event [Line Items]          
Coupon rate percentage     7.375%    
Subsequent event          
Subsequent Event [Line Items]          
Internalization, non-compete period 24 months        
Subsequent event | Wells Fargo | Amended and Restated Credit Agreement          
Subsequent Event [Line Items]          
Amount of debt agreement entered | $ $ 105.0        
Subsequent event | Crimson Midstream Holdings, LLC          
Subsequent Event [Line Items]          
Number of critical infrastructure pipeline systems | pipelineSystem 4        
Pipeline system length (in miles) | mile 2,000        
Pipeline system active length (in miles) | mile 1,300        
Subsequent event | Crimson Midstream Holdings, LLC          
Subsequent Event [Line Items]          
Percentage of interest acquired 49.50%        
Percentage of remaining interests to be acquired 50.50%        
Purchase consideration through cash on hand | $ $ 74.6        
Purchase consideration of commitments to issue new common and preferred equity | $ 118.4        
Purchase consideration through contribution of the GIGS asset to the sellers | $ 50.0        
Purchase consideration of new term loan and revolver borrowings incurred | $ 105.0        
Initial fair value of purchase consideration | $ $ 344.0        
Number of managers to be designated at Crimson | manager 2        
Number of managers at Crimson | manager 4        
Subsequent event | Crimson Midstream Holdings, LLC | Grier Members          
Subsequent Event [Line Items]          
Number of managers to be designated at Crimson | manager 2        
Subsequent event | Class C Units | Crimson Midstream Holdings, LLC          
Subsequent Event [Line Items]          
Percentage of interest acquired 49.50%        
Purchase consideration in cash (net of working capital adjustments) | $ $ 66.0        
Subsequent event | Class A-1 Units | Grier Members          
Subsequent Event [Line Items]          
Membership interest, shares issued upon exchange (in shares) 1,613,202        
Subsequent event | Class A-2 Units | Grier Members          
Subsequent Event [Line Items]          
Membership interest, shares issued upon exchange (in shares) 2,436,000        
Subsequent event | Class A-3 Units | Grier Members          
Subsequent Event [Line Items]          
Membership interest, shares issued upon exchange (in shares) 2,450,142        
Subsequent event | Class C-1 Units | Crimson Midstream Holdings, LLC          
Subsequent Event [Line Items]          
Percentage of interest acquired 49.50%        
Shares issued by acquiree through exchange (in shares) 495,000        
Subsequent event | Class C-1 Units | Crimson Midstream Holdings, LLC | Grier Members          
Subsequent Event [Line Items]          
Percentage of remaining interests to be acquired 50.50%        
Shares issued by acquiree through exchange (in shares) 505,000        
Subsequent event | Series C Preferred Stock | Class A-1 Units          
Subsequent Event [Line Items]          
Equity instrument, shares issuable upon conversion (in shares) 1,613,202        
Subsequent event | Depositary Shares | Series C Preferred Stock          
Subsequent Event [Line Items]          
Equity instrument, shares issuable upon conversion (in shares) 1,716,172        
Subsequent event | Series A Preferred Stock          
Subsequent Event [Line Items]          
Internalization, equity interest issuable (in shares) 170,213        
Subsequent event | Series B Preferred Stock | Class A-2 Units          
Subsequent Event [Line Items]          
Equity instrument, shares issuable upon conversion (in shares) 2,436,000        
Subsequent event | Common Class B          
Subsequent Event [Line Items]          
Internalization, equity interest issuable (in shares) 683,761        
Subsequent event | Common Class B | Series B Preferred Stock          
Subsequent Event [Line Items]          
Equity instrument, shares issuable upon conversion (in shares) 8,675,214        
Subsequent event | Common Class B | Class A-3 Units          
Subsequent Event [Line Items]          
Equity instrument, shares issuable upon conversion (in shares) 2,450,142        
Subsequent event | Common Stock          
Subsequent Event [Line Items]          
Dividends declared per share (in dollars per share) | $ / shares   $ 0.05      
Internalization, equity interest issuable (in shares) 1,153,846        
Subsequent event | Depositary Shares | Series A Preferred Stock          
Subsequent Event [Line Items]          
Depositary stock, dividends declared per share (in dollars per share) | $ / shares   $ 0.4609375      
Percent equivalent of preferred shares 1.00%        
Subsequent event | Preferred Stock | Series A Preferred Stock          
Subsequent Event [Line Items]          
Coupon rate percentage 7.375% 7.375%