CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Statement of Cash Flows [Abstract]
Net income	$ 12,598	$ 14,839
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	14,505	9,688
Unrealized gain on equity investment	(458)	0
Stock-based compensation	10,527	6,794
Deferred income taxes	(2,396)	1,258
Accretion of discount on marketable securities	(15)	(28)
Non-cash operating lease expense	2,998	915
Other	99	2
Changes in operating assets and liabilities:
Accounts receivable	22,942	24,083
Prepaid expenses and other current assets	547	(7,579)
Accounts payable	(13,698)	(15,125)
Accrued expenses	(5,565)	(146)
Operating lease liabilities	(2,385)	(1,044)
Other liabilities, non-current	83	106
Net cash provided by operating activities	39,782	33,763
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(12,384)	(11,808)
Capitalized software development costs	(6,777)	(4,828)
Purchases of marketable securities	(82,616)	(32,551)
Proceeds from maturities of marketable securities	28,200	21,000
Net cash used in investing activities	(73,577)	(28,187)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from issuance of common stock for employee stock purchase plan	2,402	2,635
Proceeds from exercise of stock options	838	2,078
Principal payments on finance lease obligations	(56)	0
Payments for offering costs	0	(805)
Payments to acquire treasury stock	0	(52)
Net cash provided by financing activities	3,184	3,856
NET INCREASE (DECREASE) IN CASH AND CASH EQUIVALENTS	(30,611)	9,432
CASH AND CASH EQUIVALENTS - Beginning of period	82,505	81,188
CASH AND CASH EQUIVALENTS - End of period	51,894	90,620
SUPPLEMENTAL DISCLOSURES OF CASH FLOW INFORMATION:
Income taxes paid	1,842	3,588
SUPPLEMENTAL DISCLOSURES OF NON-CASH INVESTING AND FINANCING INFORMATION:
Stock-based compensation capitalized as internal use software costs	722	361
Property and equipment included in accounts payable and accrued expenses	6,837	1,728
Capitalized software costs included in accounts payable and accrued expenses	1,047	705
Operating lease right-of-use assets obtained in exchange for new lease obligations	$ 8,867	$ 2,899