Loans and Allowance for Credit Losses Non-Performing Assets (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2013
Receivables [Abstract]
Non-accrual loans	$ 133,705	$ 133,753
Accruing loans greater than 90 days past due	21,225	20,524
Total non-performing loans	154,930	154,277
Other real estate owned (OREO)	15,300	15,052
Total non-performing assets	$ 170,230	$ 169,329