Debt Facilities - Interest Charges (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Debt Disclosure [Abstract]
Interest expense	$ 120,547	$ 134,673	$ 243,393	$ 260,950
Interest capitalized	5,910	3,484	15,764	6,798
Interest charges incurred	126,457	138,157	259,157	267,748
Interest paid, net of capitalized interest	$ 107,400	$ 111,600	$ 243,600	$ 215,300