FDIC Indemnification Asset (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012
FDIC indemnification asset components
Receivable related to claims submitted, not yet received	$ 40,401	$ 33,040	$ 18,574
Receivable related to estimated future claims on loans	45,866	62,044	79,308
Receivable related to estimated future claims on other real estate owned	6,683	7,475	19,020
FDIC indemnification asset, ending	$ 92,950	$ 102,559	$ 116,902