Annual report pursuant to Section 13 and 15(d)

Impact of Derivative Activities on Condensed Consolidated Statements of Income (Detail)

v3.20.4
Impact of Derivative Activities on Condensed Consolidated Statements of Income (Detail) - USD ($)
12 Months Ended
Dec. 31, 2020
Dec. 31, 2019
Dec. 31, 2018
Derivative Instruments, Gain (Loss) [Line Items]      
Commodity gains (losses) recognized in the Consolidated Statements of Operations $ 88,422,000 $ (68,131,000) $ 37,427,000
Cash Settlements Interest Rate Swap Operating Activities, Net (2,210,000) 0 0
Cash Settlements Commodity Operating Activities 80,297,000 (4,136,000) (48,291,000)
Commodity cash settlements and premiums received (paid) recognized in the Consolidated Statements of Cash Flows 78,087,000 (4,136,000) (48,291,000)
Gain (Loss) on Interest Rate Derivative Instruments Not Designated as Hedging Instruments (7,510,000) 0 0
Gain (Loss) on Commodity Derivative Instruments $ (95,932,000) $ 68,131,000 $ (37,427,000)