Revenue by Geographic Area (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 798,018	$ 691,449	$ 580,236
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	265,436	215,924	188,649
Japan
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	122,437	112,171	95,498
Germany
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	82,008	72,301	60,399
Canada
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	12,384	12,069	9,875
Other European
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	177,069	166,551	138,157
Other International
Revenues from External Customers and Long-Lived Assets [Line Items]
Total revenue	$ 138,684	$ 112,433	$ 87,658