Other Intangible Assets (Activity for Capitalized MSRs) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Other Intangible Assets [Roll Forward]
Total other intangible assets, Balance at beginning of year	$ 11,472
Amortization	(3,969)	(3,615)	(3,609)
Total other intangible assets, Balance at end of year	15,388	11,472
Mortgage servicing rights [Member]
Other Intangible Assets [Roll Forward]
Total other intangible assets, Balance at beginning of year	3,593	3,782	3,077
Additions	2,285	1,566	1,918
Amortization	(2,400)	(1,755)	(1,904)
Total other intangible assets, Balance at end of year	3,478	3,593	3,782
Mortgage servicing rights [Member] | OAK [Member]
Other Intangible Assets [Roll Forward]
Additions	$ 0	$ 0	$ 691