Operating Segments and Related Information Operating Segments and Related Information (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 344,517	$ 351,542
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	158,650	161,738
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	90,306	95,072
Other International
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 95,561	$ 94,732