Mortgage Servicing Rights (Schedule Of Changes In Mortgage Servicing Rights) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Mortgage Servicing Rights [Abstract]
Balance, beginning of period	$ 18,184		$ 14,454		$ 12,625
Additions for new mortgage servicing rights capitalized	17,710		6,720		5,645
Acquired mortgage servicing rights					62
Changes in fair value:
Due to changes in model inputs or assumptions, changes in fair value	(4,651)	[1]	(858)	[1]	(1,598)	[1]
Other, changes in fair value	(3,815)	[2]	(2,132)	[2]	(2,280)	[2]
Balance, end of period	$ 27,428		$ 18,184		$ 14,454

[1] Principally reflects changes in discount rates and prepayment speed assumptions, which are primarily affected by changes in interest rates.

[2] Represents changes due to collection/realization of expected cash flows over time.