Schedule II - Condensed Income Statement (Parent Only) (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
Condensed Financial Statements, Captions [Line Items]
Net investment income									$ 626,217	$ 656,429	$ 650,296
Net realized gains on investments									31,826	60,783	34,525
Fees and other income									1,303,466	1,033,805	586,730
Total revenues	$ 2,547,834	$ 2,534,156	$ 2,644,894	$ 2,598,610	$ 2,622,692	$ 2,702,488	$ 2,608,101	$ 2,448,372	10,325,494	10,381,653	9,047,657
Interest expense									55,116	58,395	77,735
Total benefits, losses and expenses									10,124,313	9,637,516	8,257,958
Income before benefit for income taxes	110,214	(32,251)	40,025	83,193	90,346	224,751	193,787	235,253	201,181	744,137	789,699
Benefit for income taxes									(59,626)	(273,230)	(300,792)
Net income	$ 65,744	$ (7,022)	$ 32,789	$ 50,044	$ 49,755	$ 140,297	$ 143,610	$ 137,245	141,555	470,907	488,907
Parent Company
Condensed Financial Statements, Captions [Line Items]
Net investment income									7,298	7,212	7,684
Net realized gains on investments									12,507	4,288	1,713
Fees and other income									95,986	90,217	89,889
Equity in net income of subsidiaries									227,805	584,464	628,894
Total revenues									343,596	686,181	728,180
General and administrative expenses									223,953	197,341	216,623
Interest expense									55,116	58,394	77,735
Total benefits, losses and expenses									279,069	255,735	294,358
Income before benefit for income taxes									64,527	430,446	433,822
Benefit for income taxes									77,028	40,461	55,085
Net income									$ 141,555	$ 470,907	$ 488,907