Commitments and Contingencies - Schedule of Components of Lease Expense (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Commitments And Contingencies Disclosure [Line Items]
Operating lease cost	$ 15,536
Variable lease expense	6,916	[1]
Short-term lease expense / costs	2,965	[2]
Sublease income	(3,496)
Total lease expense	21,921
Natural Gas and Oil Properties
Commitments And Contingencies Disclosure [Line Items]
Short-term lease expense / costs	$ 29,126	[3]

[1] Variable lease payments that are not dependent on an index or rate are not included in the lease liability or ROU assets.

[2] Short-term lease expense represents expense related to leases with a contract term of one year or less.

[3] These short-term lease costs are related to leases with a contract term of one year or less and the majority of which are related to drilling rigs and are capitalized as part of natural gas and oil properties on our consolidated balance sheets and may fluctuate based on the number of drilling rigs being utilized.