FDIC Indemnification Asset (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2012	Dec. 31, 2011
FDIC Indemnification Asset [Abstract]
Balance, beginning of period	$ 28,348	$ 0
Additions from acquisition		33,333
Accretion	65	185
Loss-share payments received from FDIC		(986)
Change in expected cash flows	(93)	(4,157)	[1]
Change in FDIC true-up provision	(60)	(27)
Balance, end of period	$ 28,260	$ 28,348

[1] The decrease was due to loan pay-offs, improved cash flow projections, and lower loss expectations for covered loans.