Segment Information (Reconciliation of Total Segment Income from Operations to Consolidated Income before Income Taxes) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting [Abstract]
Income from operations	$ 46,563	$ 254,028	$ 428,777	$ 778,682
Interest expense	(24,366)	(8,211)	(36,966)	(26,760)
Other income, net	41,265	2,636	52,091	33,790
Income before income taxes	$ 63,462	$ 248,453	$ 443,902	$ 785,712