CONDENSED CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Current assets
Cash and cash equivalents	$ 5,703	$ 14,539
Restricted cash	4,322	4,321
Accounts receivable, net	120,824	114,864
Inventory	27,470	26,689
Prepaid expenses and other current assets	12,766	14,292
Total current assets	171,085	174,705
Property and equipment, net of accumulated depreciation of $103,866 and $100,851 as of March 31, 2019 and December 31, 2018, respectively	27,798	28,788
Goodwill	367,198	367,198
Deferred taxes	1,026	1,032
Intangible assets, net of accumulated amortization of $50,640 and $49,080 as of March 31, 2019 and December 31, 2018, respectively	8,910	10,470
Operating lease right-of-use assets	19,454	0
Other non-current assets	1,719	1,745
Total assets	597,190	583,938
Current liabilities
Current portion of long-term debt	4,536	3,179
Current portion of operating lease liabilities	5,312	0
Accounts payable	77,458	67,025
Amounts due to plan sponsors	848	956
Accrued interest	2,219	6,706
Accrued expenses and other current liabilities	25,215	29,450
Total current liabilities	115,588	107,316
Long-term debt, net of current portion	506,719	501,495
Operating lease liabilities, net of current portion	19,234	0
Other non-current liabilities	15,745	25,842
Total liabilities	657,286	634,653
Stockholders’ deficit
Preferred stock, $.0001 par value; 5,000,000 shares authorized; no shares issued and outstanding as of March 31, 2019 and December 31, 2018, respectively	0	0
Common stock, $.0001 par value; 250,000,000 shares authorized; 128,567,504 shares issued and 128,160,291 shares outstanding at March 31, 2019, and 128,391,456 shares issued and 128,077,651 shares outstanding as of December 31, 2018, respectively	13	13
Treasury stock, 407,213 and 313,805 shares outstanding, at cost, as of March 31, 2019 and December 31, 2018, respectively	(1,336)	(950)
Additional paid-in capital	616,467	618,137
Accumulated deficit	(771,486)	(761,204)
Total stockholders’ deficit	(156,342)	(144,004)
Total liabilities and stockholders’ deficit	597,190	583,938
Series A convertible preferred stock, $.0001 par value; 825,000 shares authorized; 21,630 shares issued and outstanding; and $3,356 and $3,264 liquidation preference as of March 31, 2019 and December 31, 2018, respectively
Current liabilities
Convertible preferred stock	3,337	3,231
Series C convertible preferred stock, $.0001 par value; 625,000 shares authorized; 614,177 shares issued and outstanding; and $97,391 and $94,706 liquidation preference as of March 31, 2019 and December 31, 2018, respectively
Current liabilities
Convertible preferred stock	$ 92,909	$ 90,058