Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 16,963	$ 32,054
Accounts receivable, net of allowance of $5,294 and $3,529	225,315	197,990
Inventories, net	133,625	98,307
Prepaid expenses and other current assets	23,641	19,671
Assets of discontinued operations	0	77,438
Total current assets	399,544	425,460
Property, plant, and equipment, net	95,837	89,562
Operating lease assets	21,651	25,229
Goodwill	508,857	514,279
Acquired intangibles	159,734	156,365
Other assets	510	1,599
Total assets	1,186,133	1,212,494
Current liabilities:
Accounts payable	168,917	134,738
Accrued expenses	68,677	83,505
Billings in excess of cost	49,215	34,702
Liabilities of discontinued operations	0	49,295
Total current liabilities	286,809	302,240
Long-term debt	32,309	85,636
Deferred income taxes	37,555	39,057
Non-current operating lease liabilities	14,391	17,730
Other non-current liabilities	27,461	24,026
Stockholders’ equity:
Preferred stock, $0.01 par value; authorized 10,000 shares; none outstanding	0	0
Common stock, $0.01 par value; 100,000 and 50,000 shares authorized at June 30, 2021 and December 31, 2020, respectively; 33,718 shares and 33,568 shares issued and outstanding in 2021 and 2020	337	336
Additional paid-in capital	310,728	304,870
Retained earnings	508,654	469,943
Accumulated other comprehensive income (loss)	1,552	(2,461)
Cost of 1,083 and 1,028 common shares held in treasury in 2021 and 2020	(33,663)	(28,883)
Total stockholders’ equity	787,608	743,805
Total liabilities and shareholders' equity	$ 1,186,133	$ 1,212,494