Summary of Significant Accounting Policies (Details 5) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2014 item	Mar. 31, 2013	Dec. 31, 2013
Share-Based Compensation, aggregate disclosures
Employee stock-based awards, unrecognized compensation costs on nonvested awards	$ 55,903
Employee stock-based awards, unrecognized compensation costs on nonvested awards, weighted average period of recognition	2 years 2 months 12 days
Stock Options
Employee stock-based awards
Award vesting period	3 years
Certain options as a percentage of total outstanding options	28.30%
Weighted average fair value of options granted (in dollars per share)	$ 5.60	$ 7.69
Weighted average assumptions used for grants
Expected volatility (as a percent)	33.90%	33.80%
Risk-free interest rate (as a percent)	2.06%	1.13%
Expected dividend yield (as a percent)	4.00%	3.00%
Expected life of the option	6 years 9 months 18 days	6 years 3 months 18 days
Summary of option activity
Options outstanding balance, beginning of period (in shares)	5,145,739
Options granted (in shares)	525,268
Options exercised (in shares)	(136,656)
Options forfeited (in shares)	(80,463)
Options expired (in shares)	(59)
Options outstanding balance, end of period (in shares)	5,453,829
Options exercisable balance (in shares)	4,043,021
Options expected to vest (in shares)	1,297,099
Weighted Average Exercise Price
Weighted average exercise price, options outstanding balance beginning of period (in dollars per share)	$ 24.09
Weighted average exercise price, options granted (in dollars per share)	$ 30.70
Weighted average exercise price, options exercised (in dollars per share)	$ 20.63
Weighted average exercise price, options forfeited (in dollars per share)	$ 23.24
Weighted average exercise price, options expired (in dollars per share)	$ 25.31
Weighted average exercise price, options outstanding balance end of period (in dollars per share)	$ 24.79
Weighted average exercise price, options exercisable (in dollars per share)	$ 23.99
Weighted average exercise price, options expected to vest (in dollars per share)	$ 27.06
Weighted average remaining contractual term
Weighted average remaining contractual term, options outstanding	5 years 18 days
Weighted average remaining contractual term, options exercisable	4 years 1 month 24 days
Weighted average remaining contractual term, options expected to vest	7 years 8 months 8 days
Aggregate intrinsic value
Aggregate intrinsic value, options outstanding	19,635
Aggregate intrinsic value, options exercisable	16,411
Aggregate intrinsic value, options expected to vest	3,088
Aggregate intrinsic value of stock options exercised
Aggregate intrinsic value of stock options exercised	977	5,446
Stock Options | Non-Employee Directors
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
Certain options
Employee stock-based awards
Award vesting period	10 years
Contractual term of awards	12 years
Certain options as a percentage of total outstanding options	7.10%
Employee Stock Purchase Plan
Employee Stock Purchase Plan
Employee stock purchase plan, number of offering periods	2
Employee stock purchase plan, duration of offering periods	0 months	0 months	6 months
Employee stock purchase plan, maximum employee subscription rate percent	15.00%
Percentage of market price for the purchase of shares	95.00%
Employee stock purchase plan, shares issued in period	0	0
Employee Stock Purchase Plan | November 29, 2013
Employee stock-based awards
Remaining number of shares available for grant	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)	1,435,230
Granted (in shares)	598,423
Vested (in shares)	(438,353)
Forfeited (in shares)	(65,298)
Non-vested at the end of the period (in shares)	1,530,002
Weighted average grant date fair value
Weighted average grant date fair value, non-vested, beginning of period (in dollars per share)	$ 29.76
Weighted average grant date fair value, granted (in dollars per share)	$ 27.32
Weighted average grant date fair value, vested (in dollars per share)	$ 31.60
Weighted average grant date fair value, forfeited (in dollars per share)	$ 32.31
Weighted average grant date fair value, non-vested, end of period (in dollars per share)	$ 28.17
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	150	573
Cash dividends paid	221	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)	310,816
Granted (in shares)	120,785
Vested (in shares)	(148,620)
Forfeited (in shares)	(3,384)
Non-vested at the end of the period (in shares)	279,597
Weighted average grant date fair value
Weighted average grant date fair value, non-vested, beginning of period (in dollars per share)	$ 33.18
Weighted average grant date fair value, granted (in dollars per share)	$ 22.84
Weighted average grant date fair value, vested (in dollars per share)	$ 27.12
Weighted average grant date fair value, forfeited (in dollars per share)	$ 34.27
Weighted average grant date fair value, non-vested, end of period (in dollars per share)	$ 31.92
Total fair value of shares or units vested	4,030	908
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	100.00%
Performance units | Revenue or revenue growth and return on invested capital | PUs granted prior to 2014
Performance units disclosure
Performance period	1 year
Performance units | Revenue or revenue growth and return on invested capital | PUs granted in 2014
Performance units disclosure
Performance period	3 years
Performance units | Market condition associated with shareholder return of common stock
Performance units disclosure
Performance period	3 years
Performance units | Minimum | Revenue or revenue growth and return on invested capital | PUs granted prior to 2014
Performance units disclosure
Percentage payout rate	0.00%
Performance units | Minimum | Revenue or revenue growth and return on invested capital | PUs granted in 2014
Performance units disclosure
Percentage payout rate	0.00%
Performance units | Minimum | Market condition associated with shareholder return of common stock
Performance units disclosure
Percentage payout rate	0.00%
Performance units | Maximum | Revenue or revenue growth and return on invested capital | PUs granted prior to 2014
Performance units disclosure
Percentage payout rate	150.00%
Performance units | Maximum | Revenue or revenue growth and return on invested capital | PUs granted in 2014
Employee stock-based awards
Award vesting period		3 years
Performance units disclosure
Percentage payout rate	200.00%
Performance units | Maximum | Market condition associated with shareholder return of common stock
Performance units disclosure
Percentage payout rate	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)	334,548
Granted (in shares)	173,260
Vested (in shares)	(136,801)
Forfeited (in shares)	(3,384)
Non-vested at the end of the period (in shares)	367,623
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)	(23,732)
Granted (in shares)	(52,475)
Vested (in shares)	(11,819)
Non-vested at the end of the period (in shares)	(88,026)
Restricted Stock Units
Dividends accrued
Accrued cash dividends	434	1,790
Cash dividends paid	831	366
Weighted average grant date fair value
Total fair value of shares or units vested	$ 13,844	$ 8,607
Restricted Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options
Vested (in shares)	0	0