Stock Option and Incentive Plan Schedule of Stock Options Status (Details) - $ / shares	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Outstanding, Shares	553,312	558,823	294,527
Beginning Oustanding, Weighted Average Exercise Price	$ 97.21	$ 100.43	$ 101.06
Granted, Shares			252,220
Granted, Weighted Average Exercise Price			$ 104.50
Exercised, Shares	(11,447)	(21,459)
Exercised, Weighted Averge Exercise Price	$ 92.50	$ 97.04
Canceled, Shares		(2,444)
Canceled, Weighted Average Exercise Price		$ 103.57
Special dividend adjustment (shares)	5,264	18,392	12,076
Special dividend adjustment weighted average exercise price	$ 96.38	$ 97.22	$ 100.44
Ending Outstanding, Shares	547,129	553,312	558,823
Ending Oustanding, Weighted Average Exercise Pric	$ 96.38	$ 97.21	$ 100.43