FDIC Indemnification Asset (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012	Sep. 30, 2012
FDIC indemnification asset components
Receivable related to claims submitted, not yet received	$ 20,812	$ 33,040	$ 20,722
Receivable related to estimated future claims on loans	38,565	62,044	71,542
Receivable related to estimated future claims on other real estate owned	5,569	7,475	15,351
FDIC indemnification asset, ending	$ 64,946	$ 102,559	$ 107,615