Basis and Summary of Significant Accounting Policies - Changes in Accumulated Other Comprehensive Income (Loss) by Component (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 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	$ 93,000	$ 21,000	686,000	$ 24,000
Ending balance	1,459,648,000		1,459,648,000
Foreign Currency
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			(517,000)
Other comprehensive income			686,000
Ending balance	169,000		169,000
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income [Roll Forward]
Beginning balance			(517,000)
Ending balance	$ 169,000		$ 169,000