Benefit Plans Disclosure of Share-based Compensation Arrangements by Share-based Payment Award (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares
Shares
Exercised		(41,000)
First Financial Northwest, Inc. 2008 Equity Incentive Plan | Stock Options
Shares
Outstanding at beginning balance	272,000
Exercised	(54,481)
Outstanding at ending balance	217,519	272,000
Expected to Vest, Shares	217,519
Exercisable ending balance, Shares	217,519
Weighted- Average Exercise Price
Outstanding beginning balance, Weighted Average Exercise Price | $ / shares	$ 10.63
Exercised | $ / shares	8.36
Outstanding ending balance, Weighted Average Exercise Price | $ / shares	11.20	$ 10.63
Expected to Vest, Weighted Average Exercise Price | $ / shares	$ 11.20
Exercisable ending balance, Weighted Average Exercise Price	11.20
Weighted- Average Remaining Contractual Term in Years
Outstanding ending balance, Weighted Average Remaining Contractual Term	1 year 5 months 8 days
Expected to Vest, Weighted Average Remaining Contracutal Term in Years	1 year 5 months 8 days
Exercisable ending balance, Weighted Average Remaining Contracutal Term in Years	1 year 5 months 8 days
Aggregate Intrinsic Value
Outstanding beginning balance, Agregate Intrinsic Value | $	$ 1,507,300
Outstanding ending balance, Agregate Intrinsic Value | $	823,028	$ 1,507,300
Exercised | $	386,658
Expected to Vest, Aggregate Intrinsic Value | $	823,028
Exercisable ending balance, Aggregate Intrinsic Value | $	$ 823,028
First Financial Northwest, Inc. 2008 Equity Incentive Plan | Restricted Stock
Shares
Nonvested beginning balance, Shares	44,426
Granted, Shares	47,542
Vested, Shares	(58,698)
Forfeited, Shares	(1,998)
Nonvested ending balance, Shares	31,272	44,426
Expected to vest assuming a 3% forfeiture rate over the vesting term, Shares	30,334
Weighted Average Grant Date  Fair Value
Nonvested beginning balance, Weighted-Average Grant Date Fair Value | $ / shares	$ 13.78
Granted, Weighted-Average Grant Date Fair Value | $ / shares	16.35
Forfeitures, Weighted-Average Grant Date Fair Value | $ / shares	16.93
Vested, Weighted-Average Grant Date Fair Value | $ / shares	14.07
Nonvested ending balance, Weighted-Average Grant Date Fair Value | $ / shares	$ 16.93	$ 13.78