Loans (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended							3 Months Ended					9 Months Ended											9 Months Ended	3 Months Ended				9 Months Ended											9 Months Ended		3 Months Ended			9 Months Ended			3 Months Ended		9 Months Ended															9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Jun. 30, 2013	Dec. 31, 2012	Jun. 30, 2012	Dec. 31, 2011	Jun. 07, 2013 Acquired From FDIC [Member] Mountain National Bank [Member]	Sep. 30, 2012 Discharged Bankruptcy Loans [Member]	Sep. 30, 2013 Permanent Mortgage Portfolio Segment [Member]		Sep. 30, 2012 Permanent Mortgage Portfolio Segment [Member]		Sep. 30, 2013 Permanent Mortgage Portfolio Segment [Member]		Sep. 30, 2012 Permanent Mortgage Portfolio Segment [Member]		Jun. 30, 2013 Permanent Mortgage Portfolio Segment [Member]	Dec. 31, 2012 Permanent Mortgage Portfolio Segment [Member]		Jun. 30, 2012 Permanent Mortgage Portfolio Segment [Member]	Dec. 31, 2011 Permanent Mortgage Portfolio Segment [Member]	Sep. 30, 2013 Loans Held For Sale [Member]	Sep. 30, 2012 Loans Held For Sale [Member]	Sep. 30, 2013 Residential Real Estate [Member]	Sep. 30, 2013 Consumer Real Estate Portfolio Segment [Member]		Sep. 30, 2012 Consumer Real Estate Portfolio Segment [Member]		Sep. 30, 2013 Consumer Real Estate Portfolio Segment [Member]		Sep. 30, 2012 Consumer Real Estate Portfolio Segment [Member]		Jun. 30, 2013 Consumer Real Estate Portfolio Segment [Member]	Dec. 31, 2012 Consumer Real Estate Portfolio Segment [Member]		Jun. 30, 2012 Consumer Real Estate Portfolio Segment [Member]	Dec. 31, 2011 Consumer Real Estate Portfolio Segment [Member]	Sep. 30, 2013 Modified Loans Classified As Tdr [Member]	Sep. 30, 2012 Modified Loans Classified As Tdr [Member]	Sep. 30, 2013 Loans To Mortgage Companies [Member]	Sep. 30, 2012 Loans To Mortgage Companies [Member]	Sep. 30, 2013 Commercial Portfolio Segment [Member]		Sep. 30, 2012 Commercial Portfolio Segment [Member]	Sep. 30, 2013 Commercial Portfolio Segment [Member]		Sep. 30, 2012 Commercial Portfolio Segment [Member]	Sep. 30, 2013 Credit Card And Other Portfolio Segment [Member]	Sep. 30, 2012 Credit Card And Other Portfolio Segment [Member]	Sep. 30, 2013 Credit Card And Other Portfolio Segment [Member]	Sep. 30, 2012 Credit Card And Other Portfolio Segment [Member]	Jun. 30, 2013 Credit Card And Other Portfolio Segment [Member]	Dec. 31, 2012 Credit Card And Other Portfolio Segment [Member]	Jun. 30, 2012 Credit Card And Other Portfolio Segment [Member]	Dec. 31, 2011 Credit Card And Other Portfolio Segment [Member]	Sep. 30, 2013 Credit Card Class [Member]	Sep. 30, 2012 Credit Card Class [Member]	Sep. 30, 2013 Heloc And Real Estate Installment Classes [Member]	Sep. 30, 2013 Restricted Consumer Real Estate Loans And Secured Borrowings [Member]	Dec. 31, 2012 Restricted Consumer Real Estate Loans And Secured Borrowings [Member]	Sep. 30, 2012 Restricted Consumer Real Estate Loans And Secured Borrowings [Member]	Sep. 30, 2013 Restricted Permanent Mortgage Real Estate Loans And Secured Borrowings [Member]	Dec. 31, 2012 Restricted Permanent Mortgage Real Estate Loans And Secured Borrowings [Member]	Sep. 30, 2012 Restricted Permanent Mortgage Real Estate Loans And Secured Borrowings [Member]	Sep. 30, 2013 Finance And Insurance Companies [Member]	Sep. 30, 2013 Finance Insurance And Loans To Mortgage Companies [Member]	Sep. 30, 2013 Maximum [Member] Permanent Mortgage Portfolio Segment [Member]	Sep. 30, 2013 Maximum [Member] Commercial Portfolio Segment [Member]	Sep. 30, 2013 Maximum [Member] Credit Card Class [Member]	Sep. 30, 2013 Maximum [Member] Heloc And Real Estate Installment Classes [Member]	Sep. 30, 2013 Minimum [Member] Permanent Mortgage Portfolio Segment [Member]	Sep. 30, 2013 Minimum [Member] Commercial Portfolio Segment [Member]	Sep. 30, 2013 Minimum [Member] Commercial Portfolio Segment [Member] Non Accruing [Member]	Sep. 30, 2013 Minimum [Member] Credit Card Class [Member]	Sep. 30, 2013 Minimum [Member] Heloc And Real Estate Installment Classes [Member]	Sep. 30, 2013 Commercial Loan P D Grade One [Member]	Sep. 30, 2012 Commercial Loan P D Grade One [Member]	Sep. 30, 2013 Commercial Loan P D Grade One [Member] Minimum [Member] number	Sep. 30, 2013 Commercial Loan P D Grade Twelve [Member] number	Sep. 30, 2012 Commercial Loan P D Grade Twelve [Member]	Sep. 30, 2013 Commercial Loan P D Grade Thirteen [Member] number	Sep. 30, 2012 Commercial Loan P D Grade Thirteen [Member]	Sep. 30, 2013 Commercial Loan P D Grade Thirteen [Member] Minimum [Member]	Sep. 30, 2013 Commercial Loan P D Grade Fourteen [Member] number	Sep. 30, 2013 Commercial Loan P D Grade Fifteen [Member] number	Sep. 30, 2013 Commercial Loan P D Grade Sixteen [Member] Maximum [Member] number	Sep. 30, 2013 Commercial Loan L G D Grade One [Member] Minimum [Member] number	Sep. 30, 2013 Commercial Loan L G D Grade Twelve [Member] Maximum [Member] number
Accounts, Notes, Loans and Financing Receivable [Line Items]
Percentage of commercial & industrial loan portfolio																																										9.00%																									21.00%	30.00%
Concentration risk, percentage																										40.00%					35.00%											5.00%																									10.00%
Impaired commercial loans																																																																											$ 1,000,000
Troubled debt restructurings loans	385,300,000	371,400,000	385,300,000	371,400,000																				193,000,000	171,900,000
Allowance for loan losses	255,710,000	281,744,000	255,710,000	281,744,000	261,934,000	276,963,000	321,051,000	384,351,000			25,556,000		25,557,000		25,556,000		25,557,000		27,103,000	24,928,000		29,112,000	26,194,000				120,826,000		115,949,000		120,826,000		115,949,000		120,848,000	128,949,000		133,421,000	165,077,000	61,300,000	60,000,000			102,373,000		133,890,000	102,373,000		133,890,000	6,955,000	6,348,000	6,955,000	6,348,000	6,550,000	6,898,000	6,327,000	7,081,000																					81,000	54,000		2,425,000	2,709,000	8,596,000	9,211,000
Ratio of the allowance for loan losses to loans																																								16.00%	16.00%
Average balance of impaired loans	466,304,000	483,433,000	468,443,000	473,093,000																																								149,472,000		240,081,000	159,348,000		255,595,000
Interest income recognized on impaired loan	1,811,000	1,754,000	5,271,000	5,280,000																																								209,000		355,000	686,000		1,145,000
Commercial loans																																										732,701,000	1,636,683,000	8,872,800,000	[1]	9,696,305,000	8,872,800,000	[1]	9,696,305,000																		1,600,000,000							1,000,000											500,000
Forbearance agreements time period																																																																						12 months				6 months
TDR, reduction of interest rate by increment, basis points											0.25%				0.25%																																													0.25%
Modified interest rate																																																												1.00%													2.00%				1.00%
Modified interest rate time period																																																																					5 years			5 years	5 years
TDRS Maturities											40 years				40 years												30 years				30 years
Payment reductions, time period																																																																							1 year					6 months
Credit card workout program, granted rate reduction																																																										0.00%
Credit card workout program, term extension																																																										5 years
Commercial loan grades																																																																																1	12		13			14	15	16	1	12
Time period of default probability																																															1 year
Loans, net of unearned income	15,408,556,000	16,523,783,000	15,408,556,000	16,523,783,000		16,708,582,000					697,694,000	[2]	805,511,000	[2]	697,694,000	[2]	805,511,000	[2]		765,583,000	[2]						5,458,047,000	[3]	5,735,904,000	[3]	5,458,047,000	[3]	5,735,904,000	[3]		5,688,703,000	[3]					732,701,000	1,636,683,000							332,162,000	286,063,000	332,162,000	286,063,000		289,105,000			189,487,000	186,911,000		349,300,000	402,400,000	417,000,000	11,700,000	13,200,000	14,200,000
Loans acquired									249,001,000
Modified interest rate increase											1.00%				1.00%
Provision for loan losses	10,000,000	40,000,000	40,000,000	63,000,000						30,000,000	(1,022,000)		(1,400,000)		5,596,000		8,055,000										11,992,000		48,938,000		35,737,000		71,235,000																	2,535,000	2,372,000	6,211,000	5,786,000
Net charge-offs										$ 40,000,000

[1] Balance as of September 30, 2013, excludes PCI loans amounting to $47.9 million.

[2] Balances as of September 30, 2013 and 2012, and December 31, 2012 include $11.7 million, $14.2 million and $13.2 million of restricted and secured real estate loans, respectively. See Note 14 - Variable Interest Entities for additional information.

[3] Balances as of September 30, 2013 and 2012, and December 31, 2012 include $349.3 million, $417.0 million and $402.4 million of restricted and secured real estate loans, respectively. See Note 14 - Variable Interest Entities for additional information.