Stock Compensation (Nonvested Stock Roll Forward) (Details) (Restricted Stock, USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Restricted Stock
Shares
Beginning Balance	73,825	63,300	47,900
Granted	21,425	30,325	28,650
Vested	(16,875)	(17,900)	(10,900)
Forfeited	(3,900)	(1,900)	(2,350)
Ending Balance	74,475	73,825	63,300
Fair value per share (in dollars per share)
Beginning balance	$ 37.01	$ 37.69	$ 41.52
Granted	$ 51.12	$ 36.15	$ 36.59
Vested	$ 38.41	$ 38.69	$ 51.26
Forfeited	$ 37.69	$ 21.77	$ 39.30
Ending balance	$ 40.54	$ 37.01	$ 37.69
Unrecognized compensation cost	$ 1.3
Unrecognized compensation cost period (in years)	1 year 3 months 18 days