Income Taxes (Components of Provision for Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Current tax provision:
Federal	$ 54,315	$ 52,557	$ 86,623
State	5,790	(1,576)	9,866
Foreign	60,571	26,918	16,144
Total current	120,676	77,899	112,633
Deferred tax provision:
Federal	(24,383)	(37,669)	(10,994)
State	(14,080)	(17,635)	(17,794)
Foreign	(8,384)	(3,351)	(1,275)
Total deferred	(46,847)	(58,655)	(30,063)
Provision for income taxes	$ 73,829	$ 19,244	$ 82,570