CONSOLIDATED STATEMENT OF OPERATIONS - USD ($) shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Revenues:
Insurance policy income	$ 2,601.1	$ 2,556.0	$ 2,629.7
Net investment income:
General account assets	1,204.1	1,203.6	1,301.0
Policyholder and reinsurer accounts and other special-purpose portfolios	121.1	30.0	126.4
Realized investment gains (losses):
Net realized investment gains (losses), excluding impairment losses	47.9	(8.0)	64.0
Other-than-temporary impairments:
Total other-than-temporary impairment losses	(35.9)	(42.9)	(27.3)
Portion of other-than-temporary impairment losses recognized in accumulated other comprehensive income	3.6	3.0	0.0
Net impairment losses recognized	(32.3)	(39.9)	(27.3)
Gain (loss) on dissolution of variable interest entities	(7.3)	11.3	0.0
Total realized gains (losses)	8.3	(36.6)	36.7
Fee revenue and other income	50.5	58.9	50.9
Total revenues	3,985.1	3,811.9	4,144.7
Benefits and expenses:
Insurance policy benefits	2,390.5	2,308.3	2,586.2
Loss on sale of subsidiary, (gain) loss on reinsurance transactions and transition expenses	75.4	9.0	239.8
Interest expense	116.4	94.9	92.8
Amortization	253.3	260.0	247.4
Loss on extinguishment or modification of debt	0.0	32.8	0.6
Other operating costs and expenses	796.3	739.2	802.8
Total benefits and expenses	3,631.9	3,444.2	3,969.6
Income before income taxes	353.2	367.7	175.1
Income tax expense (benefit):
Tax expense on period income	127.8	129.5	159.2
Valuation allowance for deferred tax assets and other tax items	(132.8)	(32.5)	(35.5)
Net income	$ 358.2	$ 270.7	$ 51.4
Basic:
Weighted average shares outstanding (in shares)	176,638	193,054	212,917
Net income (in dollars per share)	$ 2.03	$ 1.40	$ 0.24
Diluted:
Weighted average shares outstanding (in shares)	178,323	195,166	217,655
Net income (in dollars per share)	$ 2.01	$ 1.39	$ 0.24