Fair Value Measurements - Reconciliation of the Beginning and Ending Balances for Derivative Instruments Classified as Level 3 in the Fair Value Hierarchy (Detail) - Fair Value, Inputs, Level 3 $ in Thousands	9 Months Ended
	Sep. 30, 2020 USD ($)
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Balance at December 31, 2019	$ (4,848)
Total losses included in earnings	(19,124)
Settlements, net	2,769
Transfers in and/or out of Level 3	835
Balance at September 30, 2020	$ (20,368)