Earnings Per Common Share (Schedule of Basic and Diluted Earnings Per Share) (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2011		Sep. 30, 2011		Jun. 30, 2011		Mar. 31, 2011		Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Earnings Per Share [Abstract]
Net income (loss)	$ 13,462		$ 11,880		$ 11,899		$ 8,902		$ 14,754		$ 18,872		$ 8,632		$ 5,779		$ 46,143		$ 48,037		$ 30,784
Less: Preferred dividends and accretion of issuance discount for preferred stock																	0		0		(4,947)
Net income applicable to common shareholders																	46,143		48,037		25,837
Less: Earnings allocated to participating securities																	(443)		(450)		(244)
Earnings allocated to common shareholders																	45,700		47,587		25,593
Weighted average common shares outstanding																	39,260		39,103		35,209
Earnings (loss) basic (dollars per share)	$ 0.34	[1]	$ 0.30	[1]	$ 0.30	[1]	$ 0.22	[1]	$ 0.37	[1]	$ 0.48	[1]	$ 0.22	[1]	$ 0.15	[1]	$ 1.16	[1]	$ 1.22	[1]	$ 0.73
Earnings allocated to common shareholders, Diluted																	$ 45,700		$ 47,588		$ 25,593
Weighted average number of common shares outstanding																	39,260		39,103		35,209
Dilutive effect of equity awards and warrants																	3		77		183
Weighted average diluted common shares outstanding																	39,263		39,180		35,392
Earnings (loss) diluted (dollars per share)	$ 0.34	[1]	$ 0.30	[1]	$ 0.30	[1]	$ 0.22	[1]	$ 0.37	[1]	$ 0.48	[1]	$ 0.22	[1]	$ 0.15	[1]	$ 1.16	[1]	$ 1.21	[1]	$ 0.72
Potentially dilutive share options that were not included in the computation of diluted EPS because to do so would be anti-dilutive.																	9		53		54

[1] Due to averaging of shares, quarterly earnings per share may not add up to the totals reported for the full year.