Share-Based Compensation (Narrative) (Details)		3 Months Ended
	May 13, 2021 USD ($) $ / shares shares	Mar. 31, 2022 USD ($) qtr plan shares	Mar. 31, 2021 USD ($) shares	Dec. 31, 2021 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of stock-based compensation plans | plan		3
Common stock reserved for issuance pursuant to outstanding awards | shares		340,750		351,825
Number of shares vested | shares		2,000
Aggregate fair value of outstanding restricted shares and restricted stock units | $		$ 2,300,000
Aggregate fair value of restricted shares and restricted stock units | $		73,000	$ 56,000
Proceeds from exercise of stock options | $		$ 183,000	$ 57,000
Number of shares vested | shares		0	0
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants, Forfeitures and Expirations in Period | shares		0
Unvested shares | shares		55,901		57,901
Equity based compensation expense | $		$ 353,000	$ 334,000
Unrecognized compensation cost related to non-vested equity based compensation | $		$ 2,600,000
Unrecognized equity based compensation weighted average period, years		2 years 9 months 7 days
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future issuance (in shares) | shares		87,507
Common stock reserved for issuance pursuant to outstanding awards | shares		386,651
Vesting period, years		4 years
Expiration of stock options from date of grant		7 years
Weighted average remaining contractual term, years		3 years 2 months 1 day
Aggregate intrinsic value for all options outstanding | $		$ 7,700,000
Weighted average remaining contractual term for exercisable options, years		2 years 3 months 29 days
Aggregate intrinsic value of exercisable options | $		$ 6,400,000
Aggregate intrinsic value of stock options exercised | $		228,000	78,000
Proceeds from exercise of stock options | $		183,000	57,000
Equity based compensation expense | $		$ 124,000	123,000
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period, years		4 years
Restricted stock units to common stock ratio, shares entitled, shares | shares		1
Equity based compensation expense | $		$ 140,000	123,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future issuance (in shares) | shares		129,411
Maximum contribution per plan year | $		$ 6,500
Number of shares purchased under the plan | shares
Equity based compensation expense | $		$ 34,000	32,000
Employees can purchase stock at the percentage rate of the lower of the market price on the first or last day of the offering period (as a percent)		85.00%
Employee Stock Purchase Plan | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payroll deduction for employee stock purchase plan percentage		1.00%
Employee Stock Purchase Plan | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Payroll deduction for employee stock purchase plan percentage		10.00%
Non Employee Director Stock Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for future issuance (in shares) | shares		36,000
Common stock reserved for issuance pursuant to outstanding awards | shares		8,000
Number of shares granted for non-employee directors upon re-election, shares | shares		2,000
Number of quarterly installments in which awards will vest | qtr		4
Stock issued during period, shares | shares	8,000
Stock granted, value | $	$ 224,000
Weighted average grant date fair value (in dollars per share) | $ / shares	$ 27.96
Number of shares vested | shares		6,000
Unvested shares | shares		2,000
Aggregate fair value of the unvested shares based on the closing price of entity's common stock | $		$ 81,000
Equity based compensation expense | $		$ 55,000	$ 56,000