Consolidated Statements Of Shareholders' Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock And Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Class A Common Stock [Member]	Class A Common Stock [Member] Common Stock And Additional Paid-In Capital [Member]	Class B Common Stock [Member]	Class B Common Stock [Member] Common Stock And Additional Paid-In Capital [Member]
Balance (in shares) at Dec. 31, 2014						335,452		3
Balance at December 31, 2015 at Dec. 31, 2014	$ 20,923.5	$ 17,600.0	$ 3,317.3	$ 6.2
Net income	955.3		955.3
Other comprehensive income (loss), net of tax	(100.8)			(100.8)
Dividends on common stock of $1.80 per share	(500.8)		(500.8)
Adjustments to Additional Paid in Capital, Other	9.3	9.3
Exercise of stock options (in shares)						798
Exercise of stock options	51.8	51.8
Excess tax benefits from option exercises and restricted stock vesting	6.7	6.7
Vesting of issued restricted Class A common stock, in shares						450
Vesting of issued restricted Class A common stock	(16.8)	(16.8)
Shares issued to Board of Directors, in shares						26
Shares issued to Board of Directors	2.4	2.4
Shares issued under Employee Stock Purchase Plan, in shares						10
Shares issued under Employee Stock Purchase Plan	1.0	1.0
Stock-based compensation	45.2	45.2
Balance (in shares) at Sep. 30, 2015						336,736		3
Balance at September 30, 2016 at Sep. 30, 2015	21,376.8	17,699.6	3,771.8	(94.6)
Balance (in shares) at Dec. 31, 2015					336,938	336,938	3	3
Balance at December 31, 2015 at Dec. 31, 2015	20,551.8	17,725.0	2,907.6	(80.8)
Net income	1,160.7		1,160.7
Other comprehensive income (loss), net of tax	103.7			103.7
Dividends on common stock of $1.80 per share	(609.7)		(609.7)
Exercise of stock options (in shares)						434
Exercise of stock options	29.5	29.5
Excess tax benefits from option exercises and restricted stock vesting	10.0	10.0
Vesting of issued restricted Class A common stock, in shares						570
Vesting of issued restricted Class A common stock	(26.8)	(26.8)
Shares issued to Board of Directors, in shares						26
Shares issued to Board of Directors	2.5	2.5
Shares issued under Employee Stock Purchase Plan, in shares						10
Shares issued under Employee Stock Purchase Plan	0.9	0.9
Stock-based compensation	42.3	42.3
Balance (in shares) at Sep. 30, 2016					337,978	337,978	3	3
Balance at September 30, 2016 at Sep. 30, 2016	$ 21,264.9	$ 17,783.4	$ 3,458.6	$ 22.9