Fair Value Measurements - Fair Value Hierarchy Table for Assets and Liabilities Measured at Fair Value (Detail) - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities held in the deferred compensation plans	$ 67,433,000	$ 63,942,000
Fair Value, Recurring | Commodity | Swap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(20,164,000)	6,642,000
Fair Value, Recurring | Commodity | Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(3,589,000)	3,529,000
Fair Value, Recurring | Commodity | Basis Swaps
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	9,989,000	4,491,000
Fair Value, Recurring | Commodity | Swaptions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(7,146,000)	(9,803,000)
Fair Value, Recurring | Commodity | Calls
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net		(546,000)
Fair Value, Recurring | Commodity | Three Way Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(14,030,000)	(17,818,000)
Fair Value, Recurring | Freight
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	125,000	1,104,000
Contingent Consideration | Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	19,890,000	15,960,000
Fair Value, Inputs, Level 1 | Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities held in the deferred compensation plans	67,433,000	63,942,000
Fair Value, Inputs, Level 1 | Fair Value, Recurring | Commodity | Swap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 1 | Fair Value, Recurring | Commodity | Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 1 | Fair Value, Recurring | Commodity | Basis Swaps
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 1 | Fair Value, Recurring | Commodity | Swaptions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 1 | Fair Value, Recurring | Commodity | Calls
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net		0
Fair Value, Inputs, Level 1 | Fair Value, Recurring | Commodity | Three Way Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 1 | Fair Value, Recurring | Freight
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 1 | Contingent Consideration | Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 2 | Freight | Swap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	125,000
Fair Value, Inputs, Level 2 | Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities held in the deferred compensation plans	0	0
Fair Value, Inputs, Level 2 | Fair Value, Recurring | Commodity | Swap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(20,164,000)	6,642,000
Fair Value, Inputs, Level 2 | Fair Value, Recurring | Commodity | Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	1,029,000	7,016,000
Fair Value, Inputs, Level 2 | Fair Value, Recurring | Commodity | Basis Swaps
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	9,989,000	4,491,000
Fair Value, Inputs, Level 2 | Fair Value, Recurring | Commodity | Swaptions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 2 | Fair Value, Recurring | Commodity | Calls
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net		0
Fair Value, Inputs, Level 2 | Fair Value, Recurring | Commodity | Three Way Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(14,030,000)	(17,818,000)
Fair Value, Inputs, Level 2 | Fair Value, Recurring | Freight
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	125,000	1,104,000
Fair Value, Inputs, Level 2 | Contingent Consideration | Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	19,890,000	15,960,000
Fair Value, Inputs, Level 3 | Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Trading securities held in the deferred compensation plans	0	0
Fair Value, Inputs, Level 3 | Fair Value, Recurring | Commodity | Swap
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 3 | Fair Value, Recurring | Commodity | Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(4,618,000)	(3,487,000)
Fair Value, Inputs, Level 3 | Fair Value, Recurring | Commodity | Basis Swaps
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 3 | Fair Value, Recurring | Commodity | Swaptions
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	(7,146,000)	(9,803,000)
Fair Value, Inputs, Level 3 | Fair Value, Recurring | Commodity | Calls
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net		(546,000)
Fair Value, Inputs, Level 3 | Fair Value, Recurring | Commodity | Three Way Collars
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 3 | Fair Value, Recurring | Freight
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	0	0
Fair Value, Inputs, Level 3 | Contingent Consideration | Fair Value, Recurring
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Derivative assets liabilities at fair value net	$ 0	$ 0