Operating Segments and Related Information Operating Segments and Related Information (Details 4) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 389,329	$ 338,291	$ 737,912	$ 686,743
United States
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	214,003	152,032	385,017	350,929
Europe
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	87,571	89,152	178,726	169,866
Other international
Revenues from External Customers and Long-Lived Assets [Line Items]
Revenue	$ 87,755	$ 97,107	$ 174,169	$ 165,948