Operating Segments and Related Information (Details 5) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 392,975	$ 369,380	$ 737,492	$ 720,923
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	200,276	191,108	364,240	352,846
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	95,851	85,771	188,593	180,845
Other International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 96,848	$ 92,501	$ 184,659	$ 187,232