5. Stock-based Compensation: Schedule of Options Outstanding (Details) (USD $)							0 Months Ended
	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Sep. 30, 2012 Grant Date 09/01/2003	Sep. 30, 2012 Grant Date 12/01/2003	Sep. 30, 2012 Grant Date 01/01/2004	Sep. 30, 2012 Grant Date 03/08/2004	Sep. 30, 2012 Grant Date 06/07/2004	Sep. 30, 2012 Grant Date 01/01/2005	Sep. 30, 2012 Grant Date 01/01/2006	Sep. 30, 2012 Grant Date 08/24/2006	Sep. 30, 2012 Grant Date 05/24/2007	Sep. 30, 2012 Grant Date 07/09/2007	Sep. 30, 2012 Grant Date 10/01/2007	Sep. 30, 2012 Grant Date 01/01/2008	Sep. 30, 2012 Grant Date 05/19/2008	Sep. 30, 2012 Grant Date 07/01/2008
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	68,400	72,900	72,900	75,400	82,400	82,400	2,400	3,000	5,000	7,000	2,000	18,000	4,000	3,500	2,000	1,000	2,000	14,000	2,500	2,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price	$ 22.63		$ 22.62	$ 22.59	$ 22.52	$ 22.52	$ 24.00	$ 23.65	$ 24.22	$ 21.43	$ 24.00	$ 20.55	$ 23.91	$ 23.03	$ 24.34	$ 24.61	$ 24.28	$ 23.49	$ 22.91	$ 22.91
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Date							Aug. 31, 2013	Nov. 30, 2013	Dec. 31, 2013	Mar. 08, 2014	Jun. 07, 2014	Dec. 31, 2014	Jan. 01, 2016	Aug. 24, 2016	May 24, 2017	Jul. 09, 2017	Oct. 01, 2017	Jan. 01, 2018	May 19, 2018	Jul. 01, 2018