Covered Assets and FDIC Loss-sharing Asset (FDIC Loss-sharing Asset) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Covered Assets And FDIC Loss Sharing Asset
Balance at beginning of period	$ 175,071	$ 205,991
Cash received from the FDIC	(14,804)	0
FDIC reimbursable losses, net	462	1,836
Amortization, net	(13,873)	(13,569)
Impairment	12,548	(338)
Sale of other real estate	(2,067)	(867)
Other	1,724	0
Balance at end of period	$ 159,061	$ 193,053