CONSOLIDATED STATEMENTS OF INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenues
Net premiums	$ 11,297.2	$ 10,543.8	$ 9,841.1
Investment income, net of related expenses	2,520.0	2,139.0	2,155.0
Investment related gains (losses), net:
Other-than-temporary impairments on fixed maturity securities	(31.0)	(28.0)	(43.0)
Other-than-temporary impairments on fixed maturity securities transferred to other comprehensive income	0.0	0.0	0.0
Other investment related gains (losses), net	122.0	(142.0)	211.0
Total investment related gains (losses), net	91.0	(170.0)	168.0
Other revenues	392.0	363.0	352.0
Total revenues	14,300.0	12,876.0	12,516.0
Benefits and expenses
Claims and other policy benefits	10,197.0	9,319.0	8,519.0
Interest credited	697.0	425.0	502.0
Policy acquisition costs and other insurance expenses	1,204.0	1,323.0	1,467.0
Other operating expenses	868.0	786.0	710.0
Interest expense	173.0	147.0	146.0
Collateral finance and securitization expense	29.0	30.0	29.0
Total benefits and expenses	13,168.0	12,030.0	11,373.0
Income before income taxes	1,132.0	846.0	1,143.0
Provision for income taxes	262.0	130.0	(679.0)
Net income	$ 870.0	$ 716.0	$ 1,822.0
Earnings per share
Basic earnings per share (in dollars per share)	$ 13.88	$ 11.25	$ 28.28
Diluted earnings per share (in dollars per share)	$ 13.62	$ 11.00	$ 27.71