Earnings Per Share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Sep. 30, 2012	Mar. 31, 2012	Sep. 30, 2011
Earnings Per Share [Abstract]
Net income as reported	$ 10,040		$ 6,185
Preferred stock dividend	0		(438)
Accretion of preferred stock discount	0		(203)
Net income available to common shareholders	10,040		5,544
Impact of assumed conversions
Interest on 9% convertible trust preferred securities, net of income tax	354		371
Net income available to common shareholders and assumed conversions	$ 10,394		$ 5,915
Weighted average common shares outstanding (in shares)	18,011,000		17,790,000
Incremental shares from assumed conversions of convertible trust preferred securities (in shares)	1,439,000		1,439,000
Additional dilutive common stock equivalents (in shares)	74,000		14,000
Weighted average diluted common shares outstanding (in shares)	19,524,000		19,243,000
Basic earnings per common share: (in dollars per share)	$ 0.56		$ 0.31
Diluted earnings per common share: (in dollars per share)	$ 0.53		$ 0.31
Antidilutive Securities Excluded from Computation of Earnings Per Share
Common stock equivalents excluded from earnings per share calculations due to anti-dilutive effect (in shares)		500,000		1,007,914
Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share
Common stock equivalents excluded from earnings per share calculations due to anti-dilutive effect (in shares)		28,807		324,074
Convertible Debt Securities
Debt Instrument, Interest Rate, Stated Percentage [Abstract]
Convertible trust preferred securities, interest rate, stated percentage	9.00%		9.00%