Consolidated Statements of Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues
Premium income	$ 439,731	$ 465,349	$ 445,550
Fee income	1,060,122	956,817	944,526
Other revenue	9,611	12,261	13,563
Net investment income	1,220,053	1,276,559	1,254,430
Realized investment gains (losses), net:
Total other-than-temporary (losses)	(4,152)	(4,963)	(1,044)
Other-than-temporary (losses) transferred to other comprehensive income	0	0	(78)
Other realized investment gains, net	50,555	97,845	84,832
Total realized investment gains, net	46,403	92,882	83,710
Total revenues	2,775,920	2,803,868	2,741,779
Benefits and expenses:
Life and other policy benefits	651,597	709,333	636,855
Decrease in future policy benefits	(84,251)	(124,576)	(41,636)
Interest paid or credited to contractholders	633,611	608,803	583,319
Provision for policyholders’ share of losses on participating business	(1,669)	(1,024)	(1,267)
Dividends to policyholders	41,846	48,487	57,356
Total benefits	1,241,134	1,241,023	1,234,627
General insurance expenses	1,197,613	1,181,227	1,078,996
Amortization of DAC and VOBA	19,728	31,309	100,589
Interest expense	30,943	33,705	38,588
Total benefits and expenses	2,489,418	2,487,264	2,452,800
Income before income taxes	286,502	316,604	288,979
Income tax (benefit) expense	(82,614)	85,512	98,524
Net income	$ 369,116	$ 231,092	$ 190,455