Accumulated Other Comprehensive Income Reclassifications (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013		Mar. 31, 2012
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Other income - net realized gains on sales of available for sale securities	$ 248		$ 789
Interest expense - subordinated debentures and term loans	(725)		(1,942)
Other expenses - salaries and employee benefits	(20,791)		(19,354)
Income tax expense (benefit)	(4,668)		(5,500)
NET INCOME	11,865		14,371
Amount Reclassified from Accumulated Other Comprehensive Income for the Period
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
NET INCOME	(601)		(7)
Amount Reclassified from Accumulated Other Comprehensive Income for the Period | Unrealized gains (losses) on available for sale securities
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Other income - net realized gains on sales of available for sale securities	248	[1]	789	[1]
Income tax expense (benefit)	(87)	[1]	(276)	[1]
NET INCOME	161	[1]	513	[1]
Amount Reclassified from Accumulated Other Comprehensive Income for the Period | Unrealized gains (losses) on cash flow hedges
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Interest expense - subordinated debentures and term loans	(188)	[2]		[2]
Income tax expense (benefit)	66	[2]		[2]
NET INCOME	(122)	[2]		[2]
Amount Reclassified from Accumulated Other Comprehensive Income for the Period | Unrealized gains (losses) on defined benefit plans
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Other expenses - salaries and employee benefits	(985)		(802)
Income tax expense (benefit)	345		282
NET INCOME	$ (640)		$ (520)

[1] For additional detail related to unrealized gains (losses) on available for sale securities and related amounts reclassified from accumulated other comprehensive income see NOTE 3. INVESTMENT SECURITIES.

[2] For additional detail related to unrealized gains (losses) on cash flow hedges and related amounts reclassified from accumulated other comprehensive income see NOTE 6. DERIVATIVE FINANCIAL INSTRUMENTS.