Equity Incentive Plans (Tables)

12 Months Ended

Dec. 31, 2014

Equity Incentive Plans

Assumptions used to determine the fair value of options granted

	2014		2013		2012
Weighted average expected term		6.5 years		8.2 years		9.0 years
Expected volatility		16.8 - 42.2%		19.1 - 48.1%		20.2 - 53.9%
Weighted average volatility		28.3%		31.0%		34.6%
Expected dividends		1.7 - 2.2%		1.9 - 2.2%		2.2 - 3.0%
Weighted average expected dividends		2.1%		2.2%		2.8%
Risk-free rate		0.0 - 3.0%		0.0 - 2.9%		0.0 - 2.2%

Summary of option activity

	Number (in 000s)			Weighted average exercise price		Aggregate intrinsic value (in 000s)		Weighted average remaining contractual term (years)
Outstanding as of January 1, 2014		23,982		$	40.60
Granted		2,499			52.43
Exercised		(7,750	)		40.55
Forfeited		(535	)		41.67
Expired		(207	)		56.44
Outstanding as of December 31, 2014		17,989			42.05	$	507,227		5.4
Outstanding, net of expected forfeitures		17,856			42.02		504,113		5.4
Outstanding, exercisable ("vested")		10,872			41.19		315,929		3.8

Changes in restricted stock units

	Number (in 000s)			Weighted average grant date fair value
Nonvested as of January 1, 2014		2,840		$	35.89
Granted		755			52.70
Vested		(1,098	)		32.07
Forfeited		(217	)		42.46
Nonvested as of December 31, 2014		2,280			42.71

Changes in performance stock units

	Number (in 000s)			Weighted average grant date fair value
Nonvested as of January 1, 2014		843		$	36.38
Granted		259			52.18
Adjustment for performance achievement		240			37.35
Vested		—			—
Forfeited		(38	)		36.41
Nonvested as of December 31, 2014		1,304			39.70