Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions		Common stock	Additional paid-in capital	Retained earnings (accumulated deficit) Effects of implementation of accounting change	Retained earnings (accumulated deficit)	Accumulated other comprehensive income (loss)	Treasury Stock	Noncontrolling interest	Effects of implementation of accounting change	Total
Balances (ASU 2016-13 - CECL) at Dec. 31, 2019				$ (8.4)
Balances at Dec. 31, 2019		$ 4.8	$ 10,182.6		$ 11,074.3	$ 1,037.9	$ (7,681.6)	$ 67.8		$ 14,685.8
Increase (decrease) in stockholders' equity
Common stock issued			42.8							42.8
Stock-based compensation			96.3		(9.2)					87.1
Treasury stock acquired, common							(307.0)			(307.0)
Dividends to common stockholders					(614.5)					(614.5)
Distributions to noncontrolling interest								(40.3)		(40.3)
Contributions from noncontrolling interest								6.0		6.0
Purchase of subsidiary shares from noncontrolling interest	[1]							(1.4)		(1.4)
Adjustments to redemption amount of redeemable noncontrolling interest			(0.1)					(0.1)		(0.2)
Net income (loss)	[1]				1,395.8			25.2		1,421.0
Other comprehensive income (loss)	[1]					1,345.2		1.2		1,346.4
Balances (ASU 2016-13 - CECL) at Dec. 31, 2020				$ (8.4)					$ (8.4)
Balances at Dec. 31, 2020		4.8	10,321.6		11,838.0	2,383.1	(7,988.6)	58.4		16,617.3
Increase (decrease) in stockholders' equity
Common stock issued			86.7							86.7
Stock-based compensation			106.1		(10.0)			0.1		96.2
Treasury stock acquired, common							(937.2)			(937.2)
Dividends to common stockholders					(654.1)					(654.1)
Distributions to noncontrolling interest								(33.7)		(33.7)
Contributions from noncontrolling interest								7.4		7.4
Purchase of subsidiary shares from noncontrolling interest	[1]		(16.4)					(1.7)		(18.1)
Adjustments to redemption amount of redeemable noncontrolling interest			(3.0)					(0.1)		(3.1)
Net income (loss)	[1]				1,710.6			29.3		1,739.9
Other comprehensive income (loss)	[1]					(772.2)		(3.3)		(775.5)
Balances at Dec. 31, 2021		4.8	10,495.0		12,884.5	1,610.9	(8,925.8)	56.4		16,125.8
Increase (decrease) in stockholders' equity
Common stock issued		0.1	181.6							181.7
Stock-based compensation			102.7		(11.5)			0.4		91.6
Treasury stock acquired, common							(1,661.1)			(1,661.1)
Accelerated share repurchase			(33.9)							(33.9)
Dividends to common stockholders					(642.3)					(642.3)
Distributions to noncontrolling interest								(86.2)		(86.2)
Contributions from noncontrolling interest								7.3		7.3
Purchase of subsidiary shares from noncontrolling interest	[1]		(5.7)					(2.4)		(8.1)
Adjustments to redemption amount of redeemable noncontrolling interest			0.7					(0.5)		0.2
Adjustment for reinsurance						131.8				131.8
Net income (loss)	[1]				4,811.6			66.4		4,878.0
Other comprehensive income (loss)	[1]					(8,941.7)		(0.3)		(8,942.0)
Balances at Dec. 31, 2022		$ 4.9	$ 10,740.4		$ 17,042.3	$ (7,199.0)	$ (10,586.9)	$ 41.1		$ 10,042.8

[1] Excludes amounts attributable to redeemable noncontrolling interest. See Note 14, Stockholders’ Equity, for further details.