Earnings per Share Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2016	Mar. 31, 2015
Earnings Per Share Calculation [Line Items]
Net Income, Including Portion Attributable to Noncontrolling Interest	$ 9,189	$ 9,568
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Preferred Dividends	(1,219)	(1,219)
Net income to common shareholders	7,970	8,349
Net Income Available to Common Stockholders, Diluted	$ 8,875	$ 9,225
Weighted Average Number of Shares Outstanding, Basic	24,657	24,514
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental Common Shares Attributable to Stock Options	168	219
Incremental Common Shares Attributable to Deferred Compensation	122	157
Weighted Average Number of Shares Outstanding, Diluted	30,032	29,975
Earnings Per Share, Basic	$ 0.32	$ 0.34
Earnings Per Share, Diluted	$ 0.30	$ 0.31
Anti-dilutive stock equivalent awards not included in the calculation of diluted loss per share	1,539	1,366
2017 Convertible Senior Notes [Member]
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Interest on Convertible Debt, Net of Tax	$ 385	$ 373
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental Common Shares Attributable to Conversion of Debt Securities	2,416	2,416
2018 Convertible Senior Notes [Member]
Dilutive Securities, Effect on Basic Earnings Per Share [Abstract]
Interest on Convertible Debt, Net of Tax	$ 520	$ 503
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Incremental Common Shares Attributable to Conversion of Debt Securities	2,669	2,669