Accumulated Other Comprehensive Income (Reclassification out of AOCI) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Investment securities gains, net	$ 223	$ 370
Compensation and employee benefits	31,338	21,653
Total before tax	28,640	17,111
Income tax provision	(8,796)	(4,935)
Net Income	19,844	12,176
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	223	370
Total before tax	223	370
Income tax provision	(81)	(130)
Net Income	142	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	(37)	(92)
Total before tax	(37)	(92)
Income tax provision	13	32
Net Income	$ (24)	$ (60)