General Information - Reconciliation of Total Interest Cost to Interest Expense, Net of Amounts Capitalized (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Interest Costs Incurred [Abstract]
Total interest cost, including amortization of debt issuance costs	$ 28,590	$ 27,016	$ 83,440	$ 83,888
Capitalized interest	(28)	(7,984)	(31)	(15,184)
Total interest expense as reported	$ 28,562	$ 19,032	$ 83,409	$ 68,704