Debt - Interest Expense (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
Gross interest expense	$ 383,098	$ 394,012	$ 377,666
Amortization of premium, net	(30,596)	(45,253)	(21,440)
Amortization of debt issuance costs	15,459	13,412	14,116
Interest expense before capitalization	367,961	362,171	370,342
Capitalized amounts	(64,815)	(60,808)	(61,457)
Net interest expense	303,146	301,363	308,885
Total cash paid for interest, net of amounts capitalized	$ 322,442	$ 345,916	$ 258,441