Stockholders' Equity (Rollforward Of Common Stock Table) (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Increase (Decrease) in Stockholders' Equity
Beginning (shares)	10,312,625
Repurchased common stock (shares)	0	5,000	80,512
Ending (shares)	10,340,576	10,312,625
Treasury
Increase (Decrease) in Stockholders' Equity
Beginning (shares)	803,154	894,773	873,374
Issued for stock-based compensation plans (shares)	(27,951)	(96,619)	(59,113)
Repurchased common stock (shares)		5,000	80,512
Ending (shares)	775,203	803,154	894,773
Common Stock
Increase (Decrease) in Stockholders' Equity
Beginning (shares)	10,312,625	10,221,006	10,242,405
Issued for stock-based compensation plans (shares)	27,951	96,619	59,113
Repurchased common stock (shares)		(5,000)	(80,512)
Ending (shares)	10,340,576	10,312,625	10,221,006