Schedule of Accumulated Other Comprehensive Income (Detail) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	$ (50,976)
Current period other comprehensive income	2,761	$ 2,059
Ending Balance	(14,826)
Foreign Currency Translation Adjustments
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(48,103)	(67,735)
Changes before reclassifications	2,761	2,630
Current period other comprehensive income	2,761	2,630
Ending Balance	(45,342)	(65,105)
Unrealized Losses of Available for Sale Securities
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(3,177)	(2,693)
Changes before reclassifications		(571)
Current period other comprehensive income	3,177	(571)
Ending Balance		(3,264)
Unrealized Losses of Available for Sale Securities \| ASU 2016-01
Accumulated Other Comprehensive Income Loss [Line Items]
Cumulative adjustment for adoption of ASU 2016-01	3,177
AOCI Attributable to Parent
Accumulated Other Comprehensive Income Loss [Line Items]
Beginning Balance	(51,280)	(70,428)
Changes before reclassifications	2,761	2,059
Current period other comprehensive income	5,938	2,059
Ending Balance	(45,342)	$ (68,369)
AOCI Attributable to Parent \| ASU 2016-01
Accumulated Other Comprehensive Income Loss [Line Items]
Cumulative adjustment for adoption of ASU 2016-01	$ 3,177

Other comprehensive income (loss) net of tax cumulative effect of accounting change.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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Amount after tax, before reclassification adjustments of other comprehensive income (loss).

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Amount after tax and reclassification adjustments of other comprehensive income (loss).

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Amount of stockholders' equity (deficit), net of receivables from officers, directors, owners, and affiliates of the entity, attributable to both the parent and noncontrolling interests. Amount excludes temporary equity. Alternate caption for the concept is permanent equity.

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