Basis and Summary of Significant Accounting Policies - Changes in Accumulated Other Comprehensive Loss by Component (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification out of accumulated other comprehensive loss	$ 0
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	1,481,598,000
Other Comprehensive Income	203,000	$ 593,000
Ending balance	1,500,193,000
Foreign Currency
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance	(531,000)
Other Comprehensive Income	203,000
Ending balance	$ (328,000)