Stock-Based Compensation Plans (Details 2) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Intrinsic value of options exercised	$ 9,187	$ 18,080	$ 20,028
2009 Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding intrinsic value	9,380
Options exercisable intrinsic value	$ 9,380
Options exercisable weighted average contractual life (in years)	5 years 4 months 24 days
2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	177,333
1994 Plan
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding intrinsic value	$ 2,237
Options exercisable intrinsic value	$ 2,237
Options exercisable weighted average contractual life (in years)	1 year 4 months 24 days
1994 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	22,541
40.00 - 49.99 | 1994 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	9,854
Exercise Price, lower limit (in dollars per share)	$ 40.00
Exercise Price, upper limit (in dollars per share)	$ 49.99
Weighted Average Remaining Contractual Term	2 years 1 month 6 days
70.00 - 79.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	10,607
Exercise Price, lower limit (in dollars per share)	$ 70.00
Exercise Price, upper limit (in dollars per share)	$ 79.99
Weighted Average Remaining Contractual Term	3 years 1 month 6 days
80.00 - 89.99 | 1994 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	9,506
Exercise Price, lower limit (in dollars per share)	$ 80.00
Exercise Price, upper limit (in dollars per share)	$ 89.99
Weighted Average Remaining Contractual Term	1 year 1 month 6 days
110.00 - 119.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	32,445
Exercise Price, lower limit (in dollars per share)	$ 110.00
Exercise Price, upper limit (in dollars per share)	$ 119.99
Weighted Average Remaining Contractual Term	4 years 1 month 6 days
120.00 - 129.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	29,862
Exercise Price, lower limit (in dollars per share)	$ 120.00
Exercise Price, upper limit (in dollars per share)	$ 129.99
Weighted Average Remaining Contractual Term	6 years 2 months 12 days
130.00 - 139.99 | 2009 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	104,419
Exercise Price, lower limit (in dollars per share)	$ 130.00
Exercise Price, upper limit (in dollars per share)	$ 139.99
Weighted Average Remaining Contractual Term	5 years 7 months 6 days
140.00 - 149.99 | 1994 Plan | Stock Options
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Number of Options (in shares)	3,181
Exercise Price, lower limit (in dollars per share)	$ 140.00
Exercise Price, upper limit (in dollars per share)	$ 149.99
Weighted Average Remaining Contractual Term	1 month 6 days