Allowance for Credit Losses - Summary of Activity in Allowance for Loan Losses Non-Printing (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans charged-off	$ 1,666	$ 14,239
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans charged-off	753	8,614
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Loans charged-off	$ 150	$ 4,490