Segment Information (Revenues by geographic region) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Segment Reporting Information [Line Items]
Revenues, net	$ 684,832	$ 601,138	$ 1,391,411	$ 1,269,820
United States
Segment Reporting Information [Line Items]
Revenues, net	542,803	472,258	1,117,137	1,036,083
Europe
Segment Reporting Information [Line Items]
Revenues, net	103,560	78,056	197,522	153,942
Other Geographic Locations
Segment Reporting Information [Line Items]
Revenues, net	$ 38,469	$ 50,824	$ 76,752	$ 79,795