Business Segment Information - Net Revenues and Long-Lived Assets, Related To Geographic Areas (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Geographic Information [Abstract]
Net revenues	$ 919,141	$ 812,150	$ 802,313	$ 764,917	$ 786,256	$ 747,591	$ 725,806	$ 769,126	$ 3,298,521	$ 3,028,779	$ 3,020,727
Long-lived assets	3,360,179				3,424,760				3,360,179	3,424,760
United States [Member]
Geographic Information [Abstract]
Net revenues									1,958,844	1,901,571	1,829,518
Long-lived assets	3,313,958				3,388,221				3,313,958	3,388,221
International [Member]
Geographic Information [Abstract]
Net revenues									1,339,677	1,127,208	$ 1,191,209
Long-lived assets	$ 46,221				$ 36,539				$ 46,221	$ 36,539