CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 30,466	$ 156,740	$ 56,712	$ 182,573
Other comprehensive income, net of tax:
Unrealized gain (loss) on derivative instruments and other assets	821	1,805	(843)	3,432
Foreign currency translation adjustments	0	(20,392)	48,917	(4,844)
Equity in unrealized income (loss) of an investee	0	27	0	(22)
Total comprehensive income	$ 31,287	$ 138,180	$ 104,786	$ 181,139