Earnings Per Common Share And Share Awards (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Earnings Per Common Share And Share Awards [Line Items]
Incremental dilutive potential common shares, calculated using treasury stock method (in shares)	4,310	3,826	4,923	5,238
Anti-dilutive shares excluded from computation of diluted earnings per share	7,500	3,000	4,500	0
SARs and options vesting period			1 year
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period			4,500	4,500
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Weighted Average Grant Date Fair Value [Table Text Block]			$ 31.16	$ 28.98
Compensation expense relating to SARs or options vesting			$ 103,000	$ 88,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 70,000		$ 70,000
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition			5 months
Number of stock options or SARs granted where exercise price was less than market price on date of grant			0	0
Minimum
Earnings Per Common Share And Share Awards [Line Items]
SARs and options expiration period			5 years
Annual rate at which stock appreciation rights and options are exercisable and vest			10.00%
Maximum
Earnings Per Common Share And Share Awards [Line Items]
Maximum shares of Company stock to be granted to key employees or directors			500,000
SARs and options expiration period			10 years
Annual rate at which stock appreciation rights and options are exercisable and vest			20.00%