Operating Segments and Related Information Operating Segments and Related Information (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 358,141	$ 332,230	$ 1,096,053	$ 1,018,973
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	191,261	185,222	576,278	536,150
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	81,748	61,507	260,474	231,374
Other international
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 85,132	$ 85,501	$ 259,301	$ 251,449