Stockholders' Equity - Compensation Plans (Details) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016 USD ($) multiplier $ / shares shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares
Share-based compensation
Vesting period	3 years
Tax benefit from exercise of stock options and vesting of stock awards - financing cash flow | $		$ 4,073	$ 3,218
Tax benefit from exercise of stock options and vesting of stock awards | $	$ 800	3,530	2,980
Excess tax benefits of tax deductions in recognized stock compensation expenses | $	1,000	4,100	3,200
Deficiency of tax deductions in recognized stock compensation expenses | $	$ 200	$ 600	$ 300
Stock option activity
Granted (in shares)	48,815	39,673
Stock options
Share-based compensation
Vesting period	3 years
Life of options (Expiration period)	10 years
Stock option activity
Outstanding, beginning of period (in shares)	2,939,840	3,321,063	4,010,146
Granted (in shares)	501,960	1,004,321	769,636
Forfeited (in shares)	(104,680)	(244,658)	(267,028)
Exercised (in shares)	(493,943)	(1,140,886)	(1,191,691)
Outstanding, end of period (in shares)	2,843,177	2,939,840	3,321,063
Vested and expected to vest end of period (in shares)	2,821,794
Exercisable, end of period (in shares)	1,612,850
Weighted average exercise price of stock options
Outstanding, beginning of period (in dollars per share) | $ / shares	$ 55.13	$ 50.58	$ 47.23
Granted (in dollars per share) | $ / shares	64.10	62.65	59.62
Forfeited (in dollars per share) | $ / shares	57.23	60.25	53.74
Exercised (in dollars per share) | $ / shares	50.60	47.41	44.45
Outstanding, end of period (in dollars per share) | $ / shares	57.42	$ 55.13	$ 50.58
Vested and expected to vest end of period (in dollars per share) | $ / shares	57.38
Exercisable, end of period (in dollars per share) | $ / shares	$ 53.76
Weighted average remaining contractual term
Outstanding	6 years 9 months 18 days
Vested and expected to vest	6 years 9 months 15 days
Exercisable	5 years 6 months 18 days
Aggregate intrinsic value
Outstanding | $	$ 50,684
Vested and expected to vest end of period | $	50,417
Exercisable, end of period | $	$ 34,658
Closing stock price (in dollars per share) | $ / shares	$ 75.25
Total pre-tax intrinsic value of options exercised | $	$ 9,300	$ 21,800	$ 19,700
Grants in period, weighted average grant date fair value (in dollars per share) | $ / shares	$ 15.05	$ 13.69	$ 13.49
Assumptions used for estimating value of awards granted
Risk-free interest rate (as a percent)	1.16%	1.28%	1.16%
Expected life	4 years	4 years	4 years
Expected volatility (as a percent)	27.75%	25.03%	26.20%
Expected dividend yield (as a percent)	0.00%	0.00%	0.00%
Unrecognized compensation expense | $	$ 10,900
Unrecognized compensation expense, period of recognition	1 year 8 months 19 days
Aggregate fair value of options vested | $	$ 9,300
Restricted Stock Units (RSUs)
Share-based compensation
Vesting period	3 years
Assumptions used for estimating value of awards granted
Unrecognized compensation expense | $	$ 5,800
Unrecognized compensation expense, period of recognition	1 year 6 months 7 days
Performance Based Restricted Stock Units (“PSUs”)
Share-based compensation
Vesting period	3 years	3 years
Assumptions used for estimating value of awards granted
Risk-free interest rate (as a percent)	1.00%	1.00%
Expected dividend yield (as a percent)	0.00%	0.00%
Unrecognized compensation expense | $	$ 6,100
Unrecognized compensation expense, period of recognition	1 year 11 months 19 days
2011 Management Incentive Plan
Share-based compensation
Maximum number of shares available	5,000,000
Multiplier for delivery of shares under full-value awards | multiplier	2.29
Number of shares available for grant	204,858
2014 Employee Stock Purchase Plan
Share-based compensation
Maximum number of shares available	200,000
Number of shares available for grant	128,613
2016 Management Incentive Plan
Share-based compensation
Maximum number of shares available	4,000,000
Multiplier for delivery of shares under full-value awards | multiplier	1.60
Number of shares available for grant	4,128,892