Derivatives and Hedging Activities (Details 7) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	$ 41,262	$ 46,570
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	41,262	46,570
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	108	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Pledged	47,490	50,956
Net Amount	(6,336)	(4,386)
Interest rate swaps [Member]
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	14,718	16,189
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	14,718	16,189
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Pledged	17,013	19,185
Net Amount	(2,295)	(2,996)
Loan level swaps [Member]
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	25,765	28,663
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	25,765	28,663
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	0	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Pledged	30,477	31,771
Net Amount	(4,712)	(3,108)
Foreign exchange contracts [Member]
Offsetting Liabilities [Line Items]
Gross Amounts of Recognized Liabilities	779	1,718
Gross Amounts Offset in the Statement of Financial Position	0	0
Net Amounts of Liabilities Presented in the Statement of Financial Position	779	1,718
Gross Amounts Not Offset in the Statement of Financial Position, Financial Instruments	108	0
Gross Amounts Not Offset in the Statement of Financial Position, Cash Collateral Pledged	0	0
Net Amount	$ 671	$ 1,718