Fair Value Accounting (Assets Measured at Fair Value on Nonrecurring Basis) (Details) (Fair Value, Measurements, Nonrecurring [Member], USD $) In Thousands, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Impaired Loans [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	$ 10,184	[1]	$ 29,699	[1]	$ 30,152	[1]	$ 62,506	[1]
Other Loans Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	3,315		1,183		3,546		1,288
Other Real Estate [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	363		7,580		4,513		19,925
Other Assets Held for Sale [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Assets, fair value adjustment	$ 0		$ 431		$ 170		$ 1,345

[1] Represents impaired loans that are collateral-dependent.