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, 2013	$ 492,803	$ 48,163	$ 271	$ 236,060	$ 262,625	$ (54,316)
Shares Outstanding, Beginning Balance at Dec. 31, 2013		2,000	24,357,943
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	26,186				26,186
Dividends, Preferred Stock	(2,438)				(2,438)
Stock options exercised, shares			108,848
Stock options exercised	1,460			(702)		2,162
Stock-based compensation expense	1,794			1,794
Deferral of executive and director compensation	339			339
Executive and director deferred compensation distributions shares			7,348
Executive and director deferred compensation distributions	0			(146)		146
Stockholders' Equity, Ending Balance at Jun. 30, 2014	$ 520,144	$ 48,163	$ 271	$ 237,345	$ 286,373	$ (52,008)
Shares Outstanding, Ending Balance at Jun. 30, 2014		2,000	24,474,139