Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 179,816	$ 191,363
Accounts receivable, net of allowance of $3,319 and $6,330	203,488	147,515
Inventories, net	77,943	78,476
Prepaid expenses and other current assets	20,306	19,748
Total current assets	481,553	437,102
Property, plant, and equipment, net	94,983	95,409
Operating lease assets	32,359	27,662
Goodwill	382,427	329,705
Acquired intangibles	108,821	92,592
Other assets	1,703	1,980
Total assets	1,101,846	984,450
Current liabilities:
Accounts payable	131,746	83,136
Accrued expenses	106,480	98,463
Billings in excess of cost	31,267	47,598
Total current liabilities	269,493	229,197
Deferred income taxes	40,942	40,334
Non-current operating lease liabilities	23,314	19,669
Other non-current liabilities	22,022	21,286
Shareholders’ equity:
Preferred stock, $0.01 par value; authorized 10,000 shares; none outstanding	0	0
Common stock, $0.01 par value; authorized 50,000 shares; 33,519 shares and 33,192 shares issued and outstanding in 2020 and 2019	335	332
Additional paid-in capital	302,107	295,582
Retained earnings	478,488	405,668
Accumulated other comprehensive loss	(6,220)	(5,391)
Cost of 1,024 and 906 common shares held in treasury in 2020 and 2019	(28,635)	(22,227)
Total shareholders’ equity	746,075	673,964
Total liabilities and shareholders' equity	$ 1,101,846	$ 984,450
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	50,000,000	50,000,000