SEGMENT INFORMATION - Segment Information Applicable to Reportable Operating Segments (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($) segment	Sep. 30, 2024 USD ($) segment	Sep. 30, 2023 USD ($) segment	Dec. 31, 2023 USD ($)
Segment Reporting Information
Number of reportable segments | segment	3	3	3	3
Number of operating segments | segment	3	3	3	3
Net sales:
Net sales	$ 724,717	$ 693,086	$ 2,093,221	$ 2,154,178
Operating income (loss):
Operating income (loss)	30,041	32,022	74,424	75,210
Interest income, net	4,837	2,688	14,053	5,848
Other income	1,700		1,700
Income before taxes	36,578	34,710	90,177	81,058
Depreciation and amortization:
Depreciation and amortization	3,279	3,289	9,818	9,456
Total assets:
Total assets	1,285,745	1,181,427	1,285,745	1,181,427	$ 1,188,381
Enterprise Solutions
Net sales:
Net sales	296,970	276,566	878,437	877,662
Business Solutions
Net sales:
Net sales	252,631	269,021	786,698	803,162
Public Sector Solutions
Net sales:
Net sales	175,116	147,499	428,086	473,354
Operating Segments | Enterprise Solutions
Net sales:
Net sales	296,970	276,566	878,437	877,662
Operating income (loss):
Operating income (loss)	10,280	11,230	26,357	25,263
Depreciation and amortization:
Depreciation and amortization	215	391	641	1,238
Total assets:
Total assets	717,143	676,694	717,143	676,694
Operating Segments | Business Solutions
Net sales:
Net sales	252,631	269,021	786,698	803,162
Operating income (loss):
Operating income (loss)	20,065	21,040	58,083	56,424
Depreciation and amortization:
Depreciation and amortization	155	156	465	473
Total assets:
Total assets	553,881	481,483	553,881	481,483
Operating Segments | Public Sector Solutions
Net sales:
Net sales	175,116	147,499	428,086	473,354
Operating income (loss):
Operating income (loss)	4,342	4,117	1,706	5,796
Depreciation and amortization:
Depreciation and amortization	22	22	68	61
Total assets:
Total assets	117,728	110,919	117,728	110,919
Headquarters/Other
Operating income (loss):
Operating income (loss)	(4,646)	(4,365)	(11,722)	(12,273)
Depreciation and amortization:
Depreciation and amortization	2,887	2,720	8,644	7,684
Total assets:
Assets net of intercompany balance eliminations	(103,007)	(87,669)	(103,007)	(87,669)
Intersegment Elimination
Total assets:
Total assets	$ (64,994)	$ (58,864)	$ (64,994)	$ (58,864)