Capital Stock (Tables)

3 Months Ended

Mar. 31, 2017

Capital [Abstract]

Summary of Cash Dividend Activity

A summary of the cash dividend activity for the three months ended March 31, 2017 and 2016 is as follows:

Declaration Date	Record Date	Payment Date	Cash Dividend per Share	Total
Three Months Ended March 31, 2017
February 22, 2017	March 10, 2017	March 24, 2017	$0.65	$172.2
Three Months Ended March 31, 2016
February 18, 2016	March 10, 2016	March 25, 2016	$0.65	$170.7

Summary of Share Repurchases

A summary of common stock repurchases from April 1, 2017 through April 13, 2017 (subsequent to March 31, 2017) and for the three months ended March 31, 2017 is as follows:

	April 1, 2017   Through   April 13, 2017		Three Months Ended   March 31, 2017
Shares repurchased	0.2		0.3
Average price per share	$	166.04	$	160.81
Aggregate cost	$	31.9	$	50.7
Authorization remaining at the end of the period	$	4,093.3	$	4,125.2

Summary of Stock Option Activity

A summary of stock option activity for the three months ended March 31, 2017 is as follows:

	Number of Shares		Weighted- Average Option Price per Share		Weighted- Average Remaining Contractual Life (Years)	Aggregate Intrinsic Value
Outstanding at January 1, 2017	5.6		$	102.80
Granted	1.1		166.95
Exercised	(1.1	)	83.14
Forfeited or expired	(0.1	)	107.37
Outstanding at March 31, 2017	5.5		119.24		6.52	$	254.8
Exercisable at March 31, 2017	3.1		96.31		4.58	$	217.3

Summary of Nonvested Restricted Stock Activity Including Restricted Stock Units

A summary of the status of nonvested restricted stock activity, including restricted stock units, for the three months ended March 31, 2017 is as follows:

	Restricted Stock Shares and Units		Weighted- Average Grant Date Fair Value per Share
Nonvested at January 1, 2017	2.1		$	127.68
Granted	0.5		166.94
Vested	(0.7	)	109.02
Forfeited	—		133.09
Nonvested at March 31, 2017	1.9		145.67

Summary of Weighted-Average Assumptions Used to Estimate the Fair Value of Options Granted During the Periods

The following weighted-average assumptions were used to estimate the fair values of options granted during the three months ended March 31, 2017 and 2016:

	Three Months Ended March 31
	2017		2016
Risk-free interest rate	2.31	%	1.76	%
Volatility factor	32.00	%	32.00	%
Quarterly dividend yield	0.397	%	0.491	%
Weighted-average expected life (years)	4.00		4.10

Schedule of Weighted-Average Fair Values Determined for the Periods

The following weighted-average fair values were determined for the three months ended March 31, 2017 and 2016:

	Three Months Ended March 31
	2017		2016
Options granted during the period	$	40.73	$	30.55
Restricted stock awards granted during the period	166.94		131.83