Investment Securities: Schedule of Debt Securities with Credit Loss Recognized in income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Credit losses on debt securities held April 1, 2012
Accumulated Credit Losses	$ 3,598
Additions related to increases in credit losses for which OTTI losses previously recognized
Accumulated Credit Losses	262	400	262	400
Credit losses on debt securities held June 30, 2012
Accumulated Credit Losses	3,860		3,860
Credit losses on debt securities held April 1, 2011
Accumulated Credit Losses		2,983
Credit losses on debt securities held June 30, 2011
Accumulated Credit Losses		3,383		3,383
Credit losses on debt securities held January 1, 2012
Accumulated Credit Losses			3,598
Credit losses on debt securities held January 1, 2011
Accumulated Credit Losses				$ 2,983