Shareholders' Equity, Stock Plans and Preferred Stock (Restricted Stock and Restricted Stock Units Activity) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2017 $ / shares shares
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period (in shares) | shares	153
Granted (in shares) | shares	88
Dividend Equivalents (in shares) | shares	4
Vested (in shares) | shares	(77)
Cancelled (in shares) | shares	(4)
Outstanding at beginning of period (in shares) | shares	164
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted-Average Grant Date Fair Value, Outstanding at beginning of period (in dollars per share) | $ / shares	$ 9.47
Weighted Average Grant Date Fair Value, Granted (in dollars per share) | $ / shares	9.98
Weighted Average Grant Date Fair Value, Dividend Equivalents (in dollars per share) | $ / shares	10.26
Weighted Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	9.06
Weighted-Average Grant Date Fair Value, Cancelled (in dollars per share) | $ / shares	10.10
Weighted-Average Grant Date Fair Value, Outstanding at end of period (in dollars per share) | $ / shares	$ 9.95
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Outstanding at beginning of period (in shares) | shares	54
Granted (in shares) | shares	26
Dividend Equivalents (in shares) | shares	1
Vested (in shares) | shares	(37)
Cancelled (in shares) | shares	0
Outstanding at beginning of period (in shares) | shares	44
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Roll Forward]
Weighted-Average Grant Date Fair Value, Outstanding at beginning of period (in dollars per share) | $ / shares	$ 11.10
Weighted Average Grant Date Fair Value, Granted (in dollars per share) | $ / shares	9.98
Weighted Average Grant Date Fair Value, Dividend Equivalents (in dollars per share) | $ / shares	10.26
Weighted Average Grant Date Fair Value, Vested (in dollars per share) | $ / shares	12.11
Weighted-Average Grant Date Fair Value, Cancelled (in dollars per share) | $ / shares	0.00
Weighted-Average Grant Date Fair Value, Outstanding at end of period (in dollars per share) | $ / shares	$ 9.59