Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Current assets:
Cash and cash equivalents	$ 188,203	$ 129,294
Restricted cash	647	657
Short-term investments	112,279	115,252
Accounts receivable, net	67,291	45,666
Contract assets	13,180	25,351
Inventories	136,555	133,067
Deferred cost of sales	1,676	445
Prepaid expenses and other current assets	18,544	14,966
Assets held for sale		11,180
Total current assets	538,375	475,878
Property, plant, and equipment, net	69,170	75,711
Operating lease right-of-use assets	12,981	14,453
Intangible assets, net	53,846	61,518
Goodwill	181,943	181,943
Deferred income taxes	1,555	1,549
Other assets	7,200	7,036
Total assets	865,070	818,088
Current liabilities:
Accounts payable	25,973	21,281
Accrued expenses and other current liabilities	42,306	41,243
Customer deposits and deferred revenue	58,281	54,870
Income taxes payable	923	830
Total current liabilities	127,483	118,224
Deferred income taxes	5,844	5,648
Long-term debt	317,314	300,068
Operating lease long-term liabilities	9,004	10,300
Other liabilities	10,094	9,336
Total liabilities	469,739	443,576
Stockholders' equity:
Preferred stock, $0.01 par value; 500,000 shares authorized; no shares issued and outstanding.
Common stock, $0.01 par value; 120,000,000 shares authorized; 49,618,908 shares issued and outstanding at June 30, 2020 and 48,994,346 shares issued and outstanding at December 31, 2019	497	490
Additional paid-in capital	1,100,716	1,071,058
Accumulated deficit	(707,799)	(698,930)
Accumulated other comprehensive income	1,917	1,894
Total stockholders' equity	395,331	374,512
Total liabilities and stockholders' equity	$ 865,070	$ 818,088