Long-Lived Assets, Exclusive of Deferred Income Taxes, by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Long-lived assets, exclusive of long-term investments and deferred income taxes	$ 34,439	$ 38,925
U.S.
Segment Reporting Information [Line Items]
Long-lived assets, exclusive of long-term investments and deferred income taxes	9,334	8,660
Asia Pacific
Segment Reporting Information [Line Items]
Long-lived assets, exclusive of long-term investments and deferred income taxes	304	339
Europe
Segment Reporting Information [Line Items]
Long-lived assets, exclusive of long-term investments and deferred income taxes	$ 24,801	$ 29,926