Stock Compensation Plans: Stock Options by Exercise Price (Details) - Stock Options shares in Thousands	9 Months Ended
	Jun. 30, 2023 $ / shares shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Outstanding, Number (shares) | shares	388,070
Options Outstanding, Weighed Average Exercise Price (dollars per share)	$ 23.47
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	6 years 1 month 6 days
Options Exercisable, Number (shares) | shares	201,160
Options Exercisable, Weighted Average Exercise Price (dollars per share)	$ 21.31
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	4 years 2 months 12 days
$9.00
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Exercise Price, minimum (dollars per share)	$ 9
Options Outstanding, Number (shares) | shares	14,000
Options Outstanding, Weighed Average Exercise Price (dollars per share)	$ 9.00
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	3 months 18 days
Options Exercisable, Number (shares) | shares	14,000
Options Exercisable, Weighted Average Exercise Price (dollars per share)	$ 9.00
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	3 months 18 days
$10.26 - $10.71
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Exercise Price, minimum (dollars per share)	$ 10.26
Weighted Average Exercise Price, maximum (dollars per share)	$ 10.71
Options Outstanding, Number (shares) | shares	45,000
Options Outstanding, Weighed Average Exercise Price (dollars per share)	$ 10.55
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	1 year 7 months 6 days
Options Exercisable, Number (shares) | shares	45,000
Options Exercisable, Weighted Average Exercise Price (dollars per share)	$ 10.55
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	1 year 7 months 6 days
$15.67 - $19.13
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Exercise Price, minimum (dollars per share)	$ 15.67
Weighted Average Exercise Price, maximum (dollars per share)	$ 19.13
Options Outstanding, Number (shares) | shares	74,500
Options Outstanding, Weighed Average Exercise Price (dollars per share)	$ 16.53
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	6 years 1 month 6 days
Options Exercisable, Number (shares) | shares	38,410
Options Exercisable, Weighted Average Exercise Price (dollars per share)	$ 16.18
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	4 years 10 months 24 days
$26.50 - $27.25
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Exercise Price, minimum (dollars per share)	$ 26.5
Weighted Average Exercise Price, maximum (dollars per share)	$ 27.4
Options Outstanding, Number (shares) | shares	107,820
Options Outstanding, Weighed Average Exercise Price (dollars per share)	$ 27.32
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	8 years 3 months 18 days
Options Exercisable, Number (shares) | shares	21,140
Options Exercisable, Weighted Average Exercise Price (dollars per share)	$ 27.15
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	6 years 4 months 24 days
$28.23 - $29.69
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Exercise Price, minimum (dollars per share)	$ 28.23
Weighted Average Exercise Price, maximum (dollars per share)	$ 29.69
Options Outstanding, Number (shares) | shares	111,950
Options Outstanding, Weighed Average Exercise Price (dollars per share)	$ 28.77
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	6 years 9 months 18 days
Options Exercisable, Number (shares) | shares	55,550
Options Exercisable, Weighted Average Exercise Price (dollars per share)	$ 29.33
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	5 years 2 months 12 days
$31.80
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted Average Exercise Price, minimum (dollars per share)	$ 31.8
Weighted Average Exercise Price, maximum (dollars per share)	$ 33.4
Options Outstanding, Number (shares) | shares	34,800
Options Outstanding, Weighed Average Exercise Price (dollars per share)	$ 31.85
Options Outstanding, Weighted Average Remaining Contractual Life (Years)	5 years 4 months 24 days
Options Exercisable, Number (shares) | shares	27,060
Options Exercisable, Weighted Average Exercise Price (dollars per share)	$ 31.80
Options Exercisable, Weighted Average Remaining Contractual Life (Years)	5 years 3 months 18 days