Earnings Per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Summary of numerator and denominator of the basic and fully diluted earnings per common share
Net income	$ 20,387	$ 6,968
Less: Preferred stock dividends	(34)	(181)
Less: Income attributable to participating, Income (Numerator)	(459)
Basic Earnings Per Share:
Income allocated to common stockholders, Income (Numerator)	19,894	6,787
Income allocated to common stockholders, Shares (Denominator)	10,650	6,326
Income allocated to common stockholders, Per-Share Amount	$ 1.87	$ 1.07
Diluted Earnings Per Share:
Income available to common stockholders and assumed conversions, Income (Numerator)	19,928	6,968
Income available to common stockholders and assumed conversions, Shares (Denominator)	11,031	7,901
Income available to common stockholders and assumed conversions, Per-Share Amount	$ 1.81	$ 0.88
Warrants [Member]
Effect of Dilutive Securities:
Dilutive Securities, Shares (Denominator)		128
Stock Options [Member]
Effect of Dilutive Securities:
Dilutive Securities, Shares (Denominator)	159	240
Convertible preferred stock [Member]
Effect of Dilutive Securities:
Dilutive Securities, Income (Numerator)	$ 34	$ 181
Dilutive Securities, Shares (Denominator)	222	1,207