Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 190,237	$ 178,292
Restricted cash	1,043	1,043
Accounts receivable	189,489	143,653
Inventories	139,373	142,812
Income tax receivable, net	0	2,432
Prepaid expenses and other current assets	21,166	17,157
Total current assets	541,308	485,389
Property, plant and equipment, net	419,157	407,210
Intangible assets, net	111,773	119,597
Goodwill	49,130	49,130
Deferred tax assets, net	12,654	2,834
Other assets	4,869	6,046
Total assets	1,138,891	1,070,206
Current liabilities:
Accounts payable	41,629	41,751
Accrued expenses and other current liabilities	10,552	4,831
Accrued compensation	29,259	37,882
Contingent consideration, current portion	2,852	2,372
Income taxes payable	2,771	0
Deferred revenue, current portion	9,750	13,232
Total current liabilities	96,813	100,068
Contingent consideration, net of current portion	9,839	9,902
Long-term indebtedness	13,482	13,457
Income taxes payable	12,500	12,500
Deferred revenue, net of current portion	63,255	17,259
Other liabilities	4,656	4,675
Total liabilities	200,545	157,861
Stockholders' equity:
Preferred stock, $0.001 par value; 15,000,000 shares authorized, 0 shares issued and outstanding at both June 30, 2018 and December 31, 2017	0	0
Common stock, $0.001 par value; 200,000,000 shares authorized, 51,231,814 shares issued and 50,014,528 shares outstanding at June 30, 2018; 50,619,808 shares issued and 49,405,365 shares outstanding at December 31, 2017	51	50
Treasury stock, at cost, 1,217,286 and 1,214,443 common shares at June 30, 2018 and December 31, 2017, respectively	(39,642)	(39,497)
Additional paid-in capital	632,569	618,416
Accumulated other comprehensive loss	(4,415)	(3,698)
Retained earnings	349,783	337,074
Total stockholders' equity	938,346	912,345
Total liabilities and stockholders' equity	$ 1,138,891	$ 1,070,206