Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 30,562	$ 30,924
Accounts receivable, net of allowance for doubtful accounts of $3,534 and $2,622, respectively	206,712	182,874
Unbilled revenue	49,389	32,723
Inventories	34,807	31,638
Prepaid expenses	19,638	18,772
Other current assets	32,694	24,769
Total current assets	373,802	321,700
Property and equipment, net	36,714	32,656
Intangibles and other assets:
Goodwill	199,946	202,700
Intangible assets, net	27,563	31,538
Deferred income taxes	612	1,031
Other non-current assets	1,382	1,374
Total other assets	229,503	236,643
Total assets	640,019	590,999
Current liabilities:
Accounts payable	134,609	121,289
Current portion of contingent consideration	0	19,283
Other current liabilities	34,641	35,049
Accrued expenses	33,694	30,067
Total current liabilities	202,943	205,688
Revolving credit facility	128,398	107,468
Deferred income taxes	12,348	11,291
Other long-term liabilities	6,771	1,926
Total liabilities	350,461	326,373
Commitments and Contingencies
Stockholders' equity:
Common stock, par value $0.0001 per share, 200,000 and 200,000 shares authorized, 64,075 and 63,391 shares issued, 54,055 and 54,088 shares outstanding, respectively	6	6
Additional paid-in capital	235,199	224,480
Treasury stock at cost, 10,020 and 9,303 shares, respectively	(55,873)	(49,458)
Accumulated other comprehensive loss	(19,079)	(20,799)
Retained earnings	129,305	110,397
Total stockholders' equity	289,559	264,626
Total liabilities and stockholders' equity	$ 640,019	$ 590,999