Shareholders' Equity, Stock Plans and Preferred Stock (Schedule of Stock Options Outstanding and Exercisable) (Details) - Stock Options and Stock Appreciation Rights (SARs) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Exercise Prices (in dollars per share)	$ 6.64	$ 6.97
Grants Outstanding (in shares)	211
Grants Exercisable (in shares)	211
$10.21 to $10.88
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, lower range limit (in dollars per share)	$ 10.21
Range of Exercise Prices, upper range limit (in dollars per share)	10.88
Weighted Average Exercise Prices (in dollars per share)	$ 10.63
Grants Outstanding (in shares)	44
Intrinsic Value - Grants Outstanding	$ 0
Grants Exercisable (in shares)	44
Intrinsic Value - Grants Exercisable	$ 0
$2.37 to $6.21
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Range of Exercise Prices, lower range limit (in dollars per share)	$ 2.37
Range of Exercise Prices, upper range limit (in dollars per share)	6.21
Weighted Average Exercise Prices (in dollars per share)	$ 5.56
Grants Outstanding (in shares)	167
Intrinsic Value - Grants Outstanding	$ 741
Grants Exercisable (in shares)	167
Intrinsic Value - Grants Exercisable	$ 741