Debt Facilities - Interest Charges (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Debt Disclosure [Abstract]
Interest expense	$ 92,200	$ 76,269	$ 293,395	$ 219,556
Interest capitalized	3,234	1,831	9,479	8,677
Interest charges incurred	$ 95,434	$ 78,100	$ 302,874	$ 228,233