Shared Based Awards (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Feb. 06, 2013	Feb. 01, 2012
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock compensation	$ 5,434,000	$ 5,563,000	$ 4,016,000
Tax benefit from stock-compensation cost	2,052,000	1,922,000	1,376,000
Indirect tax benefit from stock options	866,000	209,000	785,000
Stock option activity [Abstract]
Outstanding, Weighted Average Contractual Life (years)	5 years 1 month
Exercisable, Weighted Average Contractual Life (years)	4 years 0 months
Vested and Expect to Vest, Weighted Average Contractual Life (years)	5 years 1 month
Intrinsic value [Abstract]
Share Price	$ 63.71			$ 61.76	$ 46.53
Intrinsic value of stock options exercised	21,847,000	12,211,000	11,451,000
Proceeds from Stock Options Exercised	18,004,000	14,844,000	7,974,000
Tax Benefit from Stock Options Exercised	6,966,000	4,567,000	4,288,000
RSU & PRSU disclosures [Abstract]
Performance restricted stock units - percentage of grant earned	0.00%	200.00%
Performance restricted stock units earned	0	31,178
ESPP [Abstract]
Shares available employee stock purchase plan	269,905
Stock Issued During Period, Value, Employee Stock Purchase Plan	2,457,000	2,220,000	1,828,000
Stock Option [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unamortized stock compensation expense	6,600,000
Unamortized stock compensation	1 year 1 month
Employee Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Unamortized stock compensation expense	100,000
Share awards - initial authorized for issuance [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Authorized share in stock incentive plan	650,000
Share awards - total available for issuance [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Authorized share in stock incentive plan	1,654,239
Share awards available for issuance adjustment [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Authorized share in stock incentive plan	254,239
Stock Options [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Stock options granted, value	3,934,000	3,158,000	4,090,000
Expected Term, ESPP	4 years 7 months	4 years 8 months	5 years 0 months
Number of Options Granted	244,440	228,328	290,000
Fair Value Assumptions, Expected Volatility Rate	29.20%	33.60%	34.50%
Fair Value Assumptions, Risk Free Interest Rate	0.80%	0.70%	1.70%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
Granted options, weighted average exercise price	$ 62.12	$ 47.12	$ 43.27
Weighted average grant date fair value	$ 16.09	$ 13.83	$ 14.10
Stock option activity [Abstract]
Outstanding options, shares	2,444,753
Granted options, shares	244,440
Exercised options, shares	(715,779)
Forfeited options, shares	(21,290)
Outstanding options, shares	1,952,124	2,444,753
Exercisable options, shares	1,392,417
Vested and Expected to Vest, shares	1,952,124
Outstanding options, weighted average exercise price	$ 35.66
Granted options, weighted average exercise price	$ 62.12	$ 47.12	$ 43.27
Exercised options, weighted average exercise price	$ 34.48
Forfeited options, weighted average exercise price	$ 48.75
Outstanding options, weighted average exercise price	$ 39.26	$ 35.66
Exercisable options, weighted average exercise price	$ 35.18
Vested and Expect to Vest Weighted Average Exercise Price Per Share	$ 39.26
Outstanding, Aggregate intrinsic value	47,783,000
Exercisable, Intrinsic value of stock options	39,726,000
Vested and Expected to Vest, Aggregate intrinsic value	47,783,000
ESPP [Abstract]
Expected Term, ESPP	4 years 7 months	4 years 8 months	5 years 0 months
Fair Value Assumptions, Expected Volatility Rate	29.20%	33.60%	34.50%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
Restricted Stock and Performance Restricted Stock Units [Member]
RSU & PRSU disclosures [Abstract]
Restricted Stock Units, number	37,310
Restricted Stock Units Granted	19,993
Restricted Stock Units Vested	(16,526)
Restricted Stock Units Forfeited	(15,085)
RSUs & PRSUs, Nonvested, Weighted Average Grant Date Fair Value	$ 48.12	$ 45.28
Restricted Stock Units fair value	$ 54.85
Grant date fair value of restricted stock vested	$ 47.39
Grant date fair value of restricted stock forfeited	$ 50.82
Restricted Stock Units, Nonvested, Weighted Average Remaining Contractual Terms	0 years 6 months
Restricted Stock Units, Nonvested, Intrinsic Value	1,637,000
Employee Stock [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Expected Term, ESPP	0 years 6 months	0 years 6 months	0 years 6 months
Fair Value Assumptions, Expected Volatility Rate	24.40%	23.60%	26.00%
Fair Value Assumptions, Risk Free Interest Rate	0.10%	0.10%	0.40%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
ESPP [Abstract]
Employee stock purchase plan, shares issued	50,944	61,004	57,643
Stock Issued During Period, Value, Employee Stock Purchase Plan	840,000	913,000	530,000
Expected Term, ESPP	0 years 6 months	0 years 6 months	0 years 6 months
Fair Value Assumptions, Expected Volatility Rate	24.40%	23.60%	26.00%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%	0.00%
Performance Restricted Stock Units (PRSUs) [Member]
RSU & PRSU disclosures [Abstract]
Fair Value Assumptions, Risk Free Interest Rate	0.15%	0.13%
Fair Value Assumptions, Expected Dividend Rate	0.00%	0.00%
Restricted Stock Award, Forfeitures	0	0
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	15,085	15,589
Grant date fair value of restricted stock units granted	767,000	680,000
RSUs & PRSUs, Vested in Period, Intrinsic Value	$ 636,000
Restricted Stock Units fair value	$ 50.82	$ 43.60
Restricted Stock Units (RSUs) [Member]
RSU & PRSU disclosures [Abstract]
Stock Issued During Period, Shares, Restricted Stock Award, Net of Forfeitures	4,908	6,132
Grant date fair value of restricted stock units granted	$ 330,000	$ 330,000
RSUs & PRSUs, Vested in Period, Intrinsic Value	$ 412,000
Restricted Stock Units fair value	$ 67.25	$ 53.81