Accounting Policies - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Noncurrent contract assets	$ 122,500		$ 122,500
Noncurrent contract liabilities	36,900		36,900
Provisions for loss contracts	103,600		103,600		$ 71,200
Net income (loss) attributable to noncontrolling interest	1,381	$ 1,145	922	$ 2,054
Interest expense, net	58,560	31,920	103,129	52,204
Other income (expense), net	$ 2,177	$ 2,171	$ (6,051)	$ 4,757
Transferred at Point in Time
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Revenue derived from performance obligations satisfied when control passes to customer (as a percent)			75.00%