Basis and Summary of Significant Accounting Policies - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Detail) - USD ($)	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]
Reclassification out of accumulated other comprehensive income (loss)			$ 0
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			1,366,618,000
Other comprehensive income	$ (241,000)	$ (156,000)	445,000	$ (132,000)
Ending balance	1,457,096,000		1,457,096,000
Foreign Currency
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			(517,000)
Other comprehensive income			445,000
Ending balance	$ (72,000)		$ (72,000)