Investments: Available-for-sale Securities (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	$ 137,294	$ 145,216
Gross Unrealized Gains	1,087	572
Gross Unrealized Losses	(1,780)	(3,618)
Investments available-for-sale, at fair value	136,601	142,170
Mortgage-backed investments, Fannie Mae
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	15,605	24,276
Gross Unrealized Gains	128	24
Gross Unrealized Losses	(104)	(657)
Investments available-for-sale, at fair value	15,629	23,643
Mortgage-backed investments, Freddie Mac
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	4,196	6,351
Gross Unrealized Gains	96	10
Gross Unrealized Losses	0	(74)
Investments available-for-sale, at fair value	4,292	6,287
Mortgage backed investments Ginnie Mae
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	23,239	23,311
Gross Unrealized Gains	140	0
Gross Unrealized Losses	(329)	(1,250)
Investments available-for-sale, at fair value	23,050	22,061
Other
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	11,407	8,983
Gross Unrealized Gains	66	17
Gross Unrealized Losses	(25)	(21)
Investments available-for-sale, at fair value	11,448	8,979
Municipal Bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	10,675	10,615
Gross Unrealized Gains	272	49
Gross Unrealized Losses	(36)	(120)
Investments available-for-sale, at fair value	10,911	10,544
US Government agencies
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	46,672	48,190
Gross Unrealized Gains	13	73
Gross Unrealized Losses	(935)	(825)
Investments available-for-sale, at fair value	45,750	47,438
Corporate Bonds
Debt Securities, Available-for-sale [Line Items]
Amortized Cost	25,500	23,490
Gross Unrealized Gains	372	399
Gross Unrealized Losses	(351)	(671)
Investments available-for-sale, at fair value	$ 25,521	$ 23,218