Fair Value (Narrative) (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Derivatives, Fair Value [Line Items]
Other noninterest-bearing investments valued under the cost method	$ 53,600,000	$ 74,800,000
Net gains on sale of OREO properties	3,681,000	(17,166,000)	(58,676,000)
Principal amount of other real estate owned property sold	82,500,000	163,000,000
Federal Home Loan Bank Stock and Federal Reserve Bank Stock	248,400,000	255,600,000
Private equity investments prohibited by Volker rule	58,000,000
OREO Properties [Member]
Derivatives, Fair Value [Line Items]
Net gains on sale of OREO properties	15,600,000	15,300,000
Impairment of OREO properties	800,000	2,700,000
Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	2,137,259,000	1,765,214,000
Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	1,304,877,000	1,003,900,000
Third Party Pricing Service [Member] | Level 2 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	0
Third Party Pricing Service [Member] | Fair Value, Inputs, Level 3 [Member]
Derivatives, Fair Value [Line Items]
Fair value of AFS securities	$ 0