Stockholders' Equity (Rollforward of Common Stock) (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Increase (Decrease) in Stockholders' Equity
Beginning (shares)	10,340,576
Ending (shares)	10,366,007	10,340,576
Treasury
Increase (Decrease) in Stockholders' Equity
Beginning (shares)	775,203	803,154
Issued for stock-based compensation plans (shares)	(25,431)	(27,951)
Ending (shares)	749,772	775,203
Common Stock
Increase (Decrease) in Stockholders' Equity
Beginning (shares)	10,340,576	10,312,625
Issued for stock-based compensation plans (shares)	25,431	27,951
Ending (shares)	10,366,007	10,340,576