Stock Based Compensation - Options Rollforward (Details) - $ / shares	3 Months Ended	9 Months Ended
	Mar. 31, 2015	Sep. 30, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Balance	87,075	87,075
Options Granted	38,698	38,698
Exercises		(21,157)
Forfeitures		(4,945)
Ending Balance		99,671
Options Exerciseable		31,457
Weighted Average Exercise Price [Abstract]
Outstanding at Beginning of Year	$ 59.09	$ 59.09
Options Granted		87.3
Options Exercised		46.61
Options Forfeited		78.42
Outstanding at End of Period		71.73
Options Exercisable		$ 56.46
Weighted Average Contractual Term [Abstract]
Weighted Average Remaining Contractual Term, Outstanding		5 years 4 months
Weighted Average Remaining Contractual Term, Exercisable		4 years 4 months