Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 37,466,000	$ 37,260,000	$ 32,406,000
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation, amortization and impairment	6,374,000	7,505,000	5,539,000
Deferred income taxes	(277,000)	(134,000)	1,099,000
Reserve for uncertain tax positions	310,000	185,000	39,000
Gain on insurance recoveries for damaged property		(260,000)
Loss on disposal of property and equipment	7,000	12,000	(6,000)
Non-cash share-based compensation expense	623,000	680,000	1,224,000
Change in assets and liabilities:
Trade accounts receivable	343,000	(2,271,000)	311,000
Prepaid expenses and other current and long-term assets	(842,000)	(827,000)	(529,000)
Operating lease assets and liability, net	(34,000)	16,000	(8,000)
Deferred contract costs, net	783,000	(351,000)	(719,000)
Accounts payable	4,000	(247,000)	647,000
Accrued expenses, wages and bonuses	(285,000)	1,370,000	806,000
Income taxes receivable and payable	484,000	(1,529,000)	11,000
Deferred revenue	1,388,000	(773,000)	97,000
Net cash provided by operating activities	46,344,000	40,636,000	40,917,000
Cash flows from investing activities:
Purchases of property and equipment	(5,514,000)	(3,984,000)	(4,656,000)
Acquisition consideration	(3,000,000)
Insurance proceeds for damaged property		260,000
Net cash used in investing activities	(8,514,000)	(3,724,000)	(4,656,000)
Cash flows from financing activities:
Borrowings on line of credit			21,000,000
Payments on line of credit			(21,000,000)
Payments on notes payable	(4,093,000)	(3,568,000)	(3,715,000)
Payment of debt issuance costs		(36,000)
Payments on finance lease obligations	(493,000)	(332,000)	(229,000)
Proceeds from the exercise of stock options	446,000	1,734,000	0
Payment of payroll tax withholdings on share-based awards exercised	(721,000)	(2,784,000)	(1,103,000)
Repurchase of shares for treasury	(4,142,000)
Payment of dividends on common stock	(9,159,000)	(10,517,000)	(31,299,000)
Net cash used in financing activities	(18,162,000)	(15,503,000)	(36,346,000)
Effect of exchange rate changes on cash	3,000	(236,000)	611,000
Net increase (decrease) in cash and cash equivalents	19,671,000	21,173,000	526,000
Cash and cash equivalents at beginning of period	34,690,000	13,517,000	12,991,000
Cash and cash equivalents at end of period	54,361,000	34,690,000	13,517,000
Supplemental disclosure of cash paid for:
Interest expense, net of capitalized amounts	1,554,000	1,735,000	2,014,000
Income taxes	10,644,000	5,217,000	6,946,000
Supplemental disclosure of non-cash investing and financing activities:
Finance lease obligations originated for property and equipment	40,000	817,000	192,000
Stock tendered to the Company for cashless exercise of stock options in connection with equity incentive plans	1,088,000	$ 7,217,000	$ 3,618,000
Deferred acquisition consideration	$ 1,950,000