Stock Compensation (Transactions of Stock Option Plan) (Details) (Omnibus Incentive Plan, USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Number of shares (in shares)
Beginning balance	247,580	245,090	251,250
Options granted	23,258	45,100	31,500
Options exercised	(66,660)	(37,450)	(33,180)
Options forfeited	(1,800)	(5,160)	(4,480)
Ending balance	202,378	247,580	245,090
Weighted-average exercise price (in dollars per share)
Beginning balance	$ 34.26	$ 30.30	$ 26.59
Options granted	$ 51.29	$ 36.15	$ 36.59
Options exercised	$ 24.91	$ 10.25	$ 7.07
Options forfeited	$ 37.78	$ 37.19	$ 38.20
Ending balance	$ 39.27	$ 34.26	$ 30.30
Exercisable options (in shares)	113,060	141,740	152,762
Exercisable options weighted average exercise price (in dollars per share)	$ 38.18	$ 31.72	$ 25.29
Price range $9.14 — $36.15
Number of shares (in shares)
Ending balance	67,560
Weighted-average exercise price (in dollars per share)
Beginning balance	$ 32.58
Weighted average contractual life (in years)	6 years 3 months 18 days
Exercise price range - minimum (in dollars per share)	$ 9.14
Exercise price range - maximum (in dollars per share)	$ 36.15
Price range $36.16 — $38.41
Number of shares (in shares)
Ending balance	57,260
Weighted-average exercise price (in dollars per share)
Beginning balance	$ 37.57
Weighted average contractual life (in years)	6 years 9 months 18 days
Exercise price range - minimum (in dollars per share)	$ 36.16
Exercise price range - maximum (in dollars per share)	$ 38.41
Price range $38.42 — $52.81
Number of shares (in shares)
Ending balance	77,558
Weighted-average exercise price (in dollars per share)
Beginning balance	$ 46.35
Weighted average contractual life (in years)	6 years 2 months 12 days
Exercise price range - minimum (in dollars per share)	$ 38.42
Exercise price range - maximum (in dollars per share)	$ 52.81