CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Operating activities
Net loss	$ (20,521)	$ (48,214)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Amortization expense for Nucynta asset acquisition	11,064	94,340
Depreciation and amortization, excluding Nucynta asset acquisition	535	732
Stock-based compensation expense	12,562	10,180
Non-cash lease expense	409
Non-cash interest expense for Nucynta asset acquisition		17,112
Changes in operating assets and liabilities:
Accounts receivable	(6,434)	(56,564)
Inventory	(943)	(1,193)
Prepaid expenses and other assets	2,314	1,523
Accounts payable	(169)	5,995
Accrued expenses	(7,228)	11,181
Accrued rebates, returns and discounts	20,480	92,010
Operating lease assets and liabilities	734
Other long-term liabilities	(676)
Net cash provided by operating activities	12,127	127,102
Investing activities
Upfront cash paid for Nucynta asset acquisition		(18,877)
Purchases of property and equipment	(5,549)	(3,704)
Net cash used in investing activities	(5,549)	(22,581)
Financing activities
Cash paid for common stock offerings costs		(30)
Proceeds from issuances of common stock from employee stock purchase plans	817	1,117
Proceeds from term loan amendment, net of repayment of amended term loan		10,021
Repayment of asset acquisition obligations		(98,250)
Proceeds from the exercise of stock options	531	4,087
Payments made for employee restricted stock tax withholdings	(721)	(470)
Net cash provided by (used in) financing activities	627	(83,525)
Net increase in cash, cash equivalents and restricted cash	7,205	20,996
Cash, cash equivalents and restricted cash at beginning of period	146,633	118,794
Cash, cash equivalents and restricted cash at end of period	153,838	139,790
Supplemental disclosure of cash flow information
Cash paid for offering costs		30
Cash paid for interest	543	409
Supplemental disclosure of non-cash activities
Receivable from stock option exercises in other current assets	5
Acquisition of property and equipment in accounts payable and accrued expenses	552	1,456
Operating lease assets assumed	9,957
Operating lease liabilities assumed	$ 10,691
Liabilities assumed from Nucynta asset acquisition included in accrued rebates, returns and discounts		22,406
Liabilities assumed from Nucynta asset acquisition included as a reduction to accounts receivable		$ 254