Condensed Consolidated Statement of Shareholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Preferred Shares [Member]	Common Shares [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Treasury Shares [Member]
Stockholders' Equity, Beginning Balance at Dec. 31, 2014	$ 544,295	$ 48,163	$ 271	$ 238,560	$ 308,539	$ (51,238)
Shares Outstanding, Beginning Balance at Dec. 31, 2014		2,000	24,512,910
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	9,568				9,568
Dividends, Preferred Stock	(1,219)				(1,219)
Stock options exercised, shares			5,000
Stock options exercised	61			(38)		99
Stock-based compensation expense	868			868
Deferral of executive and director compensation	40			40
Executive and director deferred compensation distributions shares			419
Executive and director deferred compensation distributions	0			(9)		9
Stockholders' Equity, Ending Balance at Mar. 31, 2015	$ 553,613	$ 48,163	$ 271	$ 239,421	$ 316,888	$ (51,130)
Shares Outstanding, Ending Balance at Mar. 31, 2015		2,000	24,518,329