Fair Value Measurement (Schedule Of Reconciliation Of Assets And Liabilities Measured At Fair Value Using Significant Unobservable Inputs (Level 3) On A Recurring Basis) (Details) - Level 3 - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016
Junior Subordinated Debentures
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Junior subordinated debentures, beginning balance	$ 263,605	$ 256,917	$ 262,209	$ 255,457
Junior subordinated debentures, change included in earnings	4,872	4,380	9,552	8,674
Junior subordinated debentures, purchases and issuances	0	0	0	0
Junior subordinated debentures, sales and settlements	(3,054)	(2,637)	(6,338)	(5,471)
Junior subordinated debentures, ending balance	265,423	258,660	265,423	258,660
Junior subordinated debentures, net change in unrealized gains or (losses) relating to items held at end of period	4,872	4,380	9,552	8,674
Interest Rate Lock Commitments
Fair Value, Assets and Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Interest rate lock commitment, beginning balance	6,294	8,255	4,076	3,631
Interest rate lock commitment, change included in earnings	580	1,677	1,377	3,721
Interest rate lock commitment, purchases and issuances	11,315	16,319	21,964	31,282
Interest rate lock commitment, sales and settlements	(13,443)	(15,223)	(22,671)	(27,606)
Interest rate lock commitment, ending balance	4,746	11,028	4,746	11,028
Interest rate lock commitment, net change in unrealized gains or (losses) relating to items held at end of period	4,746	11,028	4,746	11,028
Mortgage Servicing Rights
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Mortgage servicing rights, beginning balance	142,344	117,172	142,973	131,817
Mortgage servicing rights, change included in earnings	(8,331)	(13,940)	(16,001)	(34,565)
Mortgage servicing rights, purchases and issuances	7,819	8,863	14,860	14,843
Mortgage servicing rights, sales and settlements	0	0	0	0
Mortgage servicing rights, ending balance	141,832	112,095	141,832	112,095
Mortgage servicing rights, net change in unrealized gains or (losses) relating to items held at end of period	$ (4,268)	$ (12,134)	$ (8,224)	$ (31,961)