Stock Based Compensation - Options Rollforward (Details) (USD $)	3 Months Ended
	Mar. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward]
Beginning Balance	75,251
Options Granted	37,048
Options Exercised	(3,292)
Options Forfeited	0
Ending Balance	109,007
Options Exerciseable	39,897
Weighted Average Exercise Price [Abstract]
Outstanding at Beginning of Year	$ 44.49
Options Granted	$ 73.47
Options Exercised	$ 42.24
Options Forfeited	$ 0.00
Outstanding at End of Period	$ 54.41
Options Exercisable	$ 39.64
Weighted Average Contractual Term [Abstract]
Weighted Average Remaining Contractual Term, Outstanding	5 years 7 months
Weighted Average Remaining Contractual Term, Exercisable	4 years 6 months