Income Taxes Income Taxes Details 3 (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Taxes [Abstract]
Computed tax provision at the applicable federal statutory income tax rate									$ 129,623	$ 140,910	$ 86,002
State and local taxes, net of federal income tax benefits									10,542	25,736	8,221
Dividends received deduction and tax exempt interest									(444)	(1,612)	(592)
Foreign jurisdiction differences									(5,183)	(4,424)	(3,685)
Permanent differences associated with dispositions									2,909	61,892	268
Changes in uncertain tax positions									4,046	4,624	3,710
Other									(6,466)	(1,146)	(900)
Provision for income taxes	$ (41,249)	$ (26,118)	$ (31,007)	$ (36,653)	$ (90,982)	$ (74,934)	$ (37,357)	$ (22,707)	$ 135,027	$ 225,980	$ 93,024
Total effective tax rate									36.50%	56.10%	37.90%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Percent									35.00%