Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			$ 3,246,012
Total other comprehensive income	$ 898	$ 334	1,703	$ 1,394
Ending Balance	3,258,216		3,258,216
Gains on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(3,930)
Other comprehensive income before reclassifications			789
Change in cash flow hedges reclassed to earnings			377
Total other comprehensive income			1,166
Ending Balance	(2,764)		(2,764)
Foreign Currency Items [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(262)
Other comprehensive income before reclassifications			394
Change in cash flow hedges reclassed to earnings			0
Total other comprehensive income			394
Ending Balance	132		132
Total [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance			(4,192)
Other comprehensive income before reclassifications			1,183
Change in cash flow hedges reclassed to earnings			377
Total other comprehensive income			1,560
Ending Balance	$ (2,632)		$ (2,632)