Other Comprehensive Loss - Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ 3,237,515
Other comprehensive income before reclassifications	582
Change in cash flow hedges reclassed to earnings	178	$ 172
Net current-period other comprehensive income	760
Ending Balance	3,118,701
Gains on Cash Flow Hedges [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(3,930)
Other comprehensive income before reclassifications	435
Change in cash flow hedges reclassed to earnings	178
Net current-period other comprehensive income	613
Ending Balance	(3,317)
Foreign Currency Items [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(262)
Other comprehensive income before reclassifications	147
Change in cash flow hedges reclassed to earnings	0
Net current-period other comprehensive income	147
Ending Balance	(115)
Accumulated Other Comprehensive Loss
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(4,192)
Ending Balance	$ (3,432)