Accumulated Other Comprehensive Income (Loss) - Reclassifications (Loss) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
Interest expense - subordinated debentures and term loans									$ (3,531)		$ (5,213)		$ (9,892)
Other expenses - salaries and employee benefits									(85,413)		(79,398)		(74,735)
Income tax expense	(3,187)	(2,667)	(4,155)	(4,668)	(3,153)	(3,926)	(3,288)	(5,500)	(14,677)		(15,867)		(8,655)
NET INCOME	11,447	10,403	10,815	11,865	10,310	11,236	9,205	14,371	44,530		45,122		25,252
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) for the Period
Reclassification Adjustments out of Accumulated Other Comprehensive Income [Line Items]
NET INCOME									(1,438)		1,478		1,749
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) 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									487	[1]	2,389	[1]	2,439	[1]
Income tax expense									(170)	[1]	(835)	[1]	(854)	[1]
NET INCOME									317	[1]	1,554	[1]	1,585	[1]
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) 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									(935)	[2]	(217)	[2]		[2]
Income tax expense									327	[2]	76	[2]		[2]
NET INCOME									(608)	[2]	(141)	[2]		[2]
Amount Reclassified from Accumulated Other Comprehensive Income (Loss) 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									(1,765)		100		252
Income tax expense									618		(35)		(88)
NET INCOME									$ (1,147)		$ 65		$ 164

[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 5. 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 13. DERIVATIVE INSTRUMENTS AND HEDGING ACTIVITIES.