Condensed Consolidated Statements of Equity - USD ($) shares in Millions, $ in Millions	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	AOCI Attributable to Parent [Member]	Parent [Member]	Noncontrolling Interest [Member]
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ 1,175.8	$ 1.3	$ 41.1	$ 1,457.4	$ (330.3)	$ 1,169.5	$ 6.3
Common Stock, Shares, Outstanding		1,309.1
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	760.4	$ 0.0	0.0	760.6	0.0	760.6	(0.2)
Other comprehensive income/(loss)	(12.9)	0.0	0.0	0.0	(12.9)	(12.9)	0.0
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	98.0	0.0	98.0	0.0	0.0	98.0	0.0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	45.0	0.0	45.0	0.0	0.0	45.0	0.0
Stock Issued During Period, Value, Employee Stock Purchase Plan	8.1	0.0	8.1	0.0	0.0	8.1	0.0
Stock Repurchased and Retired During Period, Value	(5,000.0)	(0.1)	(151.1)	(4,848.8)	0.0	(5,000.0)	0.0
Dividends, Cash	(448.8)	$ 0.0	0.0	(448.8)	0.0	(448.8)	0.0
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture		6.0
Stock Issued During Period, Shares, Employee Stock Purchase Plans		0.2
Stock Repurchased and Retired During Period, Shares		(72.0)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(2,878.8)	$ 1.2	41.1	(2,584.0)	(343.2)	(2,884.9)	6.1
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 495.6	$ 0.0	0.0	495.6	0.0	495.6	0.0
Common Stock, Shares, Outstanding		1,243.3
Dividends Payable, Amount Per Share	$ 0.36
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	$ (6,231.0)	$ 1.2	41.1	(5,771.2)	(503.3)	(6,232.2)	1.2
Common Stock, Shares, Outstanding		1,184.6
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	885.3	$ 0.0	0.0	885.7	0.0	885.7	(0.4)
Other comprehensive income/(loss)	111.1	0.0	0.0	0.0	111.1	111.1	0.0
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	91.3	0.0	91.3	0.0	0.0	91.3	0.0
Shares Issued, Value, Share-based Payment Arrangement, after Forfeiture	(54.1)	0.0	(54.1)	0.0	0.0	(54.1)	0.0
Stock Issued During Period, Value, Employee Stock Purchase Plan	8.9	0.0	8.9	0.0	0.0	8.9	0.0
Stock Repurchased and Retired During Period, Value	(1,107.9)	0.0	(46.1)	(1,061.8)	0.0	(1,107.9)	0.0
Dividends, Cash	(480.0)	$ 0.0	0.0	(480.0)	0.0	(480.0)	0.0
Shares Issued, Shares, Share-based Payment Arrangement, after Forfeiture		2.8
Stock Issued During Period, Shares, Employee Stock Purchase Plans		0.1
Stock Repurchased and Retired During Period, Shares		(13.0)
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	(6,759.1)	$ 1.2	41.1	(6,414.8)	(387.4)	(6,759.9)	0.8
Cumulative Effect of New Accounting Principle in Period of Adoption	$ 17.3	$ 0.0	$ 0.0	$ 12.5	$ 4.8	$ 17.3	$ 0.0
Common Stock, Shares, Outstanding		1,174.5
Dividends Payable, Amount Per Share	$ 0.41