Net Revenues by Geographic Area (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Segment Reporting Information [Line Items]
Net revenues	$ 164,506	[1]	$ 136,496	[1]	$ 481,914	[1]	$ 417,201	[1]
United States
Segment Reporting Information [Line Items]
Net revenues	123,904	[1]	105,173	[1]	365,596	[1]	319,269	[1]
the Netherlands
Segment Reporting Information [Line Items]
Net revenues	26,494	[1]	24,193	[1]	89,952	[1]	79,273	[1]
Other international
Segment Reporting Information [Line Items]
Net revenues	$ 14,108	[1]	$ 7,130	[1]	$ 26,366	[1]	$ 18,659	[1]

[1] .