Summary of Significant Accounting Policies (Details 5) (USD $)	1 Months Ended	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Share-Based Compensation, aggregate disclosures
Employee stock-based awards, unrecognized compensation costs on nonvested awards		$ 58,648,000		$ 58,648,000
Employee stock-based awards, unrecognized compensation costs on nonvested awards, weighted average period of recognition				2 years 3 months 18 days
Stock Options
Employee stock-based awards
Weighted average fair value of options granted (in dollars per share)				$ 7.69	$ 7.00
Weighted average assumptions used for grants
Expected volatility (as a percent)				33.80%	33.80%
Risk-free interest rate (as a percent)				1.13%	1.24%
Expected dividend yield (as a percent)				3.00%	3.00%
Expected life of the option				6 years 3 months 18 days	6 years 3 months 18 days
Summary of option activity
Options outstanding balance, beginning of period (in shares)				5,908,102
Options granted (in shares)				261,698
Options exercised (in shares)				(746,486)
Options forfeited (in shares)				(80,496)
Options expired (in shares)				(1,961)
Options outstanding balance, end of period (in shares)		5,340,857		5,340,857
Options exercisable balance (in shares)		3,737,433		3,737,433
Options expected to vest (in shares)		1,505,421		1,505,421
Weighted Average Exercise Price
Weighted average exercise price, options outstanding balance beginning of period (in dollars per share)				$ 23.39
Weighted average exercise price, options granted (in dollars per share)				$ 33.03
Weighted average exercise price, options exercised (in dollars per share)				$ 22.41
Weighted average exercise price, options forfeited (in dollars per share)				$ 21.72
Weighted average exercise price, options expired (in dollars per share)				$ 23.86
Weighted average exercise price, options outstanding balance end of period (in dollars per share)		$ 24.02		$ 24.02
Weighted average exercise price, options exercisable (in dollars per share)		$ 23.71		$ 23.71
Weighted average exercise price, options expected to vest (in dollars per share)		$ 24.70		$ 24.70
Weighted average remaining contractual term
Weighted average remaining contractual term, options outstanding				5 years 8 months 16 days
Weighted average remaining contractual term, options exercisable				5 years 25 days
Weighted average remaining contractual term, options expected to vest				7 years 2 months 19 days
Aggregate intrinsic value
Aggregate intrinsic value, options outstanding		17,521,000		17,521,000
Aggregate intrinsic value, options exercisable		12,725,000		12,725,000
Aggregate intrinsic value, options expected to vest		4,528,000		4,528,000
Aggregate intrinsic value of stock options exercised
Aggregate intrinsic value of stock options exercised		4,650,000	2,308,000	10,096,000	3,372,000
Stock Options | Director
Employee stock-based awards
Award vesting period				1 year
Majority of stock options
Employee stock-based awards
Award vesting period				5 years
Contractual term of awards				10 years
A portion of stock options effective 2007
Employee stock-based awards
Award vesting period				10 years
Contractual term of awards				12 years
Certain options as a percentage of total outstanding options		10.30%		10.30%
Certain options beginning in 2011
Employee stock-based awards
Award vesting period				3 years
Contractual term of awards				10 years
Certain options as a percentage of total outstanding options		20.40%		20.40%
Employee Stock Purchase Plan
Employee Stock Purchase Plan
Employee stock purchase plan, number of offering periods		2		2
Employee stock purchase plan, duration of offering periods				6 months
Employee stock purchase plan, maximum employee subscription rate percent		15.00%		15.00%
Percentage of market price for the purchase of shares				95.00%
Employee stock purchase plan, shares issued in period				74,732	88,672
Remaining number of shares available for grant		204,494		204,494
Additional shares authorized for grant				1,000,000
Employee Stock Purchase Plan | November 29, 2013
Employee Stock Purchase Plan
Remaining number of shares available for grant		1,000,000		1,000,000
Restricted Stock and Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options
Non-vested at the beginning of the period (in shares)				1,303,664
Granted (in shares)				611,489
Vested (in shares)				(407,310)
Forfeited (in shares)				(37,821)
Non-vested at the end of the period (in shares)		1,470,022		1,470,022
Weighted average grant date fair value
Weighted average grant date fair value, non-vested, beginning of period (in dollars per share)				$ 29.89
Weighted average grant date fair value, granted (in dollars per share)				$ 35.71
Weighted average grant date fair value, vested (in dollars per share)				$ 29.65
Weighted average grant date fair value, forfeited (in dollars per share)				$ 29.43
Weighted average grant date fair value, non-vested, end of period (in dollars per share)		$ 32.39		$ 32.39
Restricted Stock and Restricted Stock Units | Minimum
Employee stock-based awards
Award vesting period				3 years
Restricted Stock and Restricted Stock Units | Maximum
Employee stock-based awards
Award vesting period				5 years
Performance units
Dividends accrued
Accrued cash dividends		148,000		389,000
Cash dividends paid		0	0	0	0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options
Non-vested at the beginning of the period (in shares)				231,646
Granted (in shares)				176,797
Vested (in shares)				(30,803)
Forfeited (in shares)				(3,347)
Non-vested at the end of the period (in shares)		374,293		374,293
Weighted average grant date fair value
Weighted average grant date fair value, non-vested, beginning of period (in dollars per share)				$ 29.12
Weighted average grant date fair value, granted (in dollars per share)				$ 38.75
Weighted average grant date fair value, vested (in dollars per share)				$ 29.48
Weighted average grant date fair value, forfeited (in dollars per share)				$ 28.87
Weighted average grant date fair value, non-vested, end of period (in dollars per share)		$ 33.64		$ 33.64
Total fair value of shares or units vested		0		908,000
Performance units disclosure
Period of anniversary from the date of grant				1 year
Qualifying age for grant of performance units				55 years
Qualifying service period				10 years
Percentage of achievement of the predefined revenue and ROIC targets		86.60%		86.60%
Performance units | Revenue growth and return on invested capital
Performance units disclosure
Performance period				1 year
Performance units | Market condition associated with shareholder return of common stock
Employee stock-based awards
Award vesting period				3 years
Performance units disclosure
Performance period				3 years
Performance units | Minimum | Revenue growth and return on invested capital
Employee stock-based awards
Award vesting period				1 year
Performance units disclosure
Percentage payout rate		0.00%		0.00%
Performance units | Minimum | Market condition associated with shareholder return of common stock
Performance units disclosure
Percentage payout rate		0.00%		0.00%
Performance units | Maximum | Revenue growth and return on invested capital
Employee stock-based awards
Award vesting period				3 years
Performance units disclosure
Percentage payout rate		150.00%		150.00%
Performance units | Maximum | Market condition associated with shareholder return of common stock
Performance units disclosure
Percentage payout rate		200.00%		200.00%
Original PU Awards
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options
Non-vested at the beginning of the period (in shares)				236,093
Granted (in shares)				202,333
Vested (in shares)				(31,361)
Forfeited (in shares)				(3,347)
Non-vested at the end of the period (in shares)		403,718		403,718
PUs Adjustment
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options
Non-vested at the beginning of the period (in shares)				(4,447)
Granted (in shares)				(25,536)
Vested (in shares)				558
Non-vested at the end of the period (in shares)		(29,425)		(29,425)
Restricted Stock Units
Dividends accrued
Accrued cash dividends	34,000	350,000	0	1,098,000	0
Cash dividends paid		187,000		553,000
Weighted average grant date fair value
Total fair value of shares or units vested		3,469,000	1,985,000	12,076,000	5,964,000
Restricted Stock Plan
Weighted average grant date fair value
Total fair value of shares or units vested		$ 1,000	$ 1,000	$ 1,000	$ 1,000