Other Comprehensive Income (Loss) - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			$ 3,455,185
Other comprehensive income before reclassifications			1,283
Change in cash flow hedges reclassed to earnings	$ 172	$ 172	516	$ 1,001
Net current-period other comprehensive income			1,799
Ending Balance	3,272,071		3,272,071
Gains on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(6,109)
Other comprehensive income before reclassifications			950
Change in cash flow hedges reclassed to earnings			516
Net current-period other comprehensive income			1,466
Ending Balance	(4,643)		(4,643)
Foreign Currency Items [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(174)
Other comprehensive income before reclassifications			333
Change in cash flow hedges reclassed to earnings			0
Net current-period other comprehensive income			333
Ending Balance	159		159
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(6,283)
Ending Balance	$ (4,484)		$ (4,484)