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, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Segment Reporting [Abstract]
Income from operations	$ 254,028	$ 306,761	$ 778,682	$ 821,604
Interest expense	(8,211)	(9,486)	(26,760)	(28,182)
Other income, net	2,636	(2,670)	33,790	4,440
Income before income taxes	$ 248,453	$ 294,605	$ 785,712	$ 797,862