Condensed Consolidated Balance Sheets (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Preferred stock
Preferred stock, shares authorized	5,000,000	5,000,000
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares issued	25,331,541	25,307,110
Common stock, shares outstanding	25,331,541	25,307,110
Accumulated other comprehensive income, tax expense (in dollars)	$ 1,069	$ 2,745
Series A senior preferred stock
Preferred stock
Preferred stock, per share stated value (in dollars per share)	$ 1,000	$ 1,000
Preferred stock, shares issued	21,000	21,000
Preferred stock, shares outstanding	21,000	21,000
Series C preferred stock
Preferred stock
Preferred stock, per share stated value (in dollars per share)	$ 3.25	$ 3.25
Preferred stock, shares issued	1,189,538	1,189,538
Preferred stock, shares outstanding	1,189,538	1,189,538