Fair Value Measurements - Financial Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Assets:
Publicly traded equity securities	$ 159	$ 2,779
Derivative instruments	38,447	76,640
Liabilities:
Derivative instruments	415,628	45,832
Fair value, measurements, recurring
Assets:
Publicly traded equity securities	159	2,779
Derivative instruments	11,699	57,707
Assets	627,302	954,616
Liabilities:
Derivative instruments	400,459	35,612
Fair value, measurements, recurring | Money market and deposit accounts
Assets:
Investments	611,071	886,547
Fair value, measurements, recurring | Certificates of deposit
Assets:
Investments	4,373	7,583
Fair value, measurements, recurring | Fair value, Inputs, Level 1
Assets:
Publicly traded equity securities	159	2,779
Derivative instruments	0	0
Assets	611,230	889,326
Liabilities:
Derivative instruments	0	0
Fair value, measurements, recurring | Fair value, Inputs, Level 1 | Money market and deposit accounts
Assets:
Investments	611,071	886,547
Fair value, measurements, recurring | Fair value, Inputs, Level 1 | Certificates of deposit
Assets:
Investments	0	0
Fair value, measurements, recurring | Fair value, Inputs, Level 2
Assets:
Publicly traded equity securities	0	0
Derivative instruments	11,699	57,707
Assets	16,072	65,290
Liabilities:
Derivative instruments	400,459	35,612
Fair value, measurements, recurring | Fair value, Inputs, Level 2 | Money market and deposit accounts
Assets:
Investments	0	0
Fair value, measurements, recurring | Fair value, Inputs, Level 2 | Certificates of deposit
Assets:
Investments	$ 4,373	$ 7,583