Securities Available for Sale (Details)	3 Months Ended		12 Months Ended
	Mar. 31, 2021 USD ($) Security	Mar. 31, 2020 USD ($)	Dec. 31, 2014 USD ($)	Dec. 31, 2012 USD ($)	Dec. 31, 2020 USD ($)
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	$ 159,964,000				$ 155,732,000
Gross unrealized gains	4,052,000				5,008,000
Gross unrealized losses	(1,753,000)				(1,121,000)
Fair Value	162,263,000				159,619,000
Amortized cost of investment securities by contractual maturity [Abstract]
Due within one year	9,390,000
Due after one year through five years	33,922,000
Due after five years through ten years	17,143,000
Due after ten years	5,119,000
Mortgage-related securities	94,390,000
Amortized Cost	159,964,000				155,732,000
Fair value of investment securities by contractual maturity [Abstract]
Due within one year	9,456,000
Due after one year through five years	34,913,000
Due after five years through ten years	16,649,000
Due after ten years	5,122,000
Mortgage-related securities	96,123,000
Fair Value	162,263,000				159,619,000
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	29,903,000				6,969,000
12 months or longer	8,907,000				8,907,000
Fair value	38,810,000				15,876,000
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(660,000)				(28,000)
12 months or longer	(1,093,000)				(1,093,000)
Unrealized loss	(1,753,000)				(1,121,000)
Mortgage-Backed Securities [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	23,862,000				24,005,000
Gross unrealized gains	868,000				1,110,000
Gross unrealized losses	(152,000)				(15,000)
Fair Value	24,578,000				25,100,000
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	23,862,000				24,005,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	24,578,000				25,100,000
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	4,308,000				2,089,000
12 months or longer	0				0
Fair value	4,308,000				2,089,000
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(152,000)				(15,000)
12 months or longer	0				0
Unrealized loss	(152,000)				(15,000)
Collateralized Mortgage Obligations, Government Sponsored Enterprise Issued [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	67,447,000				61,604,000
Gross unrealized gains	1,428,000				1,693,000
Gross unrealized losses	(460,000)				(13,000)
Fair Value	68,415,000				63,284,000
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	67,447,000				61,604,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	68,415,000				63,284,000
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	19,956,000				4,880,000
12 months or longer	0				0
Fair value	19,956,000				4,880,000
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(460,000)				(13,000)
12 months or longer	0				0
Unrealized loss	(460,000)				(13,000)
Collateralized Mortgage Obligations, Private label Issued [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	3,081,000				3,611,000
Gross unrealized gains	49,000				54,000
Gross unrealized losses	0				0
Fair Value	3,130,000				3,665,000
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	3,081,000				3,611,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	3,130,000				3,665,000
Mortgage-Related Securities [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	94,390,000				89,220,000
Gross unrealized gains	2,345,000				2,857,000
Gross unrealized losses	(612,000)				(28,000)
Fair Value	96,123,000				92,049,000
Securities pledged as collateral	687,000				785,000
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	94,390,000				89,220,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	96,123,000				92,049,000
Government Sponsored Enterprise Bonds [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	2,500,000				2,500,000
Gross unrealized gains	0				3,000
Gross unrealized losses	(32,000)				0
Fair Value	2,468,000				2,503,000
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	2,500,000				2,500,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	2,468,000				2,503,000
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	2,468,000
12 months or longer	0
Fair value	2,468,000
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(32,000)
12 months or longer	0
Unrealized loss	(32,000)
Municipal Securities [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	50,574,000				51,512,000
Gross unrealized gains	1,683,000				2,102,000
Gross unrealized losses	(16,000)				0
Fair Value	$ 52,241,000				53,614,000
Number of securities that were other-than-temporarily impaired | Security	1
Credit losses charged to earnings with respect to municipal security				$ 77,000
Additional credit loss charged to earnings			$ 17,000
Amortized Cost	$ 116,000
Impairment on securities	94,000
Proceeds from sales of investment securities	0	$ 0
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	50,574,000				51,512,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	52,241,000				53,614,000
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	3,171,000				0
12 months or longer	0				0
Fair value	3,171,000				0
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	(16,000)				0
12 months or longer	0				0
Unrealized loss	(16,000)				0
Other Debt Securities [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	12,500,000				12,500,000
Gross unrealized gains	24,000				46,000
Gross unrealized losses	(1,093,000)				(1,093,000)
Fair Value	11,431,000				11,453,000
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	12,500,000				12,500,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	11,431,000				11,453,000
Fair value of securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	0				0
12 months or longer	8,907,000				8,907,000
Fair value	8,907,000				8,907,000
Unrealized loss on securities available for sale in a continuous unrealized loss position [Abstract]
Less than 12 months	0				0
12 months or longer	(1,093,000)				(1,093,000)
Unrealized loss	(1,093,000)				(1,093,000)
Debt Securities [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Amortized Cost	65,574,000				66,512,000
Gross unrealized gains	1,707,000				2,151,000
Gross unrealized losses	(1,141,000)				(1,093,000)
Fair Value	$ 66,140,000				67,570,000
Number of securities that were in unrealized loss position twelve months or longer | Security	1
Amortized cost of investment securities by contractual maturity [Abstract]
Amortized Cost	$ 65,574,000				66,512,000
Fair value of investment securities by contractual maturity [Abstract]
Fair Value	$ 66,140,000				67,570,000
Back-to-Back Swaps [Member]
Available-for-sale Securities, Fair Value to Amortized Cost Basis [Abstract]
Securities pledged as collateral					$ 7,200,000