Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 120,859	$ 191,363
Accounts receivable, net of allowance of $6,270 and $6,330	193,609	147,515
Inventories	79,058	78,476
Prepaid expenses and other current assets	22,849	19,748
Total current assets	416,375	437,102
Property, plant, and equipment, net	94,723	95,409
Operating lease assets	33,383	27,662
Goodwill	378,740	329,705
Acquired intangibles	110,481	92,592
Other assets	1,794	1,980
Total assets	1,035,496	984,450
Current liabilities:
Accounts payable	116,853	83,136
Accrued expenses	94,009	98,463
Billings in excess of cost	29,281	47,598
Total current liabilities	240,143	229,197
Deferred income taxes	40,022	40,334
Non-current operating lease liabilities	24,400	19,669
Other non-current liabilities	21,167	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; 33,413 shares and 33,192 shares issued and outstanding in 2020 and 2019	334	332
Additional paid-in capital	299,829	295,582
Retained earnings	444,728	405,668
Accumulated other comprehensive loss	(8,438)	(5,391)
Cost of 993 and 906 common shares held in treasury in 2020 and 2019	(26,689)	(22,227)
Total shareholders’ equity	709,764	673,964
Total liabilities and shareholders' equity	$ 1,035,496	$ 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