Accumulated Other Comprehensive Income (Reclassification out of AOCI) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net	$ 370	$ 62
Compensation and employee benefits	21,653	21,995
Total before tax	17,111	12,100
Income tax provision	(4,935)	(3,198)
Net Income	12,176	8,902
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Available-for-Sale Securities [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net	370
Total before tax	370
Income tax provision	(130)
Net Income	240
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized Gains and Losses on Pension Plan Liability [Member]
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Compensation and employee benefits	(92)
Total before tax	(92)
Income tax provision	32
Net Income	$ (60)