Covered Assets and FDIC Loss-sharing Asset (FDIC Loss-sharing Asset) (Details) (FDIC Loss-sharing Asset [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
FDIC Loss-sharing Asset [Member]
Covered Assets And FDIC Loss Sharing Asset [Line Items]
Balance at beginning of period	$ 175,071	$ 205,991
Established through acquisitions	0	68,734
Cash received from the FDIC	(54,649)	(54,200)
FDIC reimbursable losses, net	399	4,042
Amortization, net	(42,940)	(46,049)
Impairment	20,714	(1,318)
Sale of other real estate	(7,789)	(4,346)
Other	358	743
Balance at end of period	$ 96,354	$ 175,071