Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015
Cash flows from operating activities:
Net cash provided by operating activities	$ 457,457	$ 356,792
Proceeds from sales, maturities and redemptions of investments:
Fixed maturities, available-for-sale	4,056,220	3,723,042
Mortgage loans on real estate	128,908	179,363
Limited partnership interests, other corporation interests and other investments	7,642	3,033
Purchases of investments:
Fixed maturities, available-for-sale	(2,837,403)	(1,762,463)
Mortgage loans on real estate	(374,710)	(177,185)
Limited partnership interests, other corporation interests and other investments	(3,234)	(883)
Net change in short-term investments	(2,150,029)	(2,371,057)
Net change in policy loans	6,723	(396)
Purchases of furniture, equipment and software	(20,652)	(40,551)
Net cash used in investing activities	(1,186,535)	(447,097)
Cash flows from financing activities:
Contract deposits	1,766,662	1,090,823
Contract withdrawals	(978,575)	(794,349)
Net change in due to/from parent and affiliates	1,067	(9,444)
Dividends paid	(104,831)	(112,110)
Payments for and interest paid on financing element derivatives, net	(5,111)	(7,572)
Net change in commercial paper borrowings	6,298	(100)
Net change in book overdrafts	17,613	3,887
Income tax benefit on share-based compensation	405	594
Net cash provided by financing activities	703,528	171,729
Net (decrease) increase in cash	(25,550)	81,424
Cash, beginning of year	34,362	12,775
Cash, end of period	8,812	94,199
Net cash paid during the year for:
Income taxes	(16,391)	(20,505)
Interest	(18,798)	(18,632)
Non-cash investing and financing transactions during the years:
Share-based compensation expense	$ 1,059	$ 781