Commitments, Contingencies And Guarantees (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Operating leases, rent expense	$ 6,800	$ 6,700	$ 6,500
Commitments outstanding		324,817
Outstanding purchase commitments expected to fund in the next 12 months	67,400
Notional amount of underlying swaps	1,184,666	$ 797,030
Financial Standby Letter Of Credit [Member]
Carrying value of the guarantee obligations, liability	2,800
Commitments outstanding	311,844
State Tax Credits [Member]
Purchases of state tax credits	39,300
Sales of state tax credits	21,700
Risk Participation Agreement [Member]
Carrying value of the guarantee obligations, liability	195
Notional amount of underlying swaps	$ 58,500
Risk Participation Agreement [Member] | Minimum [Member]
Risk Participation Agreements, Term	3 years
Risk Participation Agreement [Member] | Maximum [Member]
Risk Participation Agreements, Term	11 years