Consolidated Statements of Changes in Stockholder's Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated other comprehensive income (loss)
Beginning balance (in shares) at Dec. 31, 2017		45,528,519
Beginning balance at Dec. 31, 2017	$ 46,513	$ 0	$ 486,570	$ (436,821)	$ (3,236)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock—option exercise (in shares)		80,000
Issuance of common stock—option exercise	112		112
Issuance of common stock—restricted stock (in shares)		2,171,778
Issuance of common stock - Innovatus (in shares)		15,333,333
Issuance of common stock	21,325	$ 1	21,324
Compensation expense related to issued stock options and restricted stock awards	1,784		1,784
Net loss	(26,058)			(26,058)
Other comprehensive income (loss)	974				974
Ending balance (in shares) at Jun. 30, 2018		63,113,630
Ending balance at Jun. 30, 2018	49,169	$ 1	509,790	(458,360)	(2,262)
Beginning balance (in shares) at Mar. 31, 2018		60,838,526
Beginning balance at Mar. 31, 2018	60,297	$ 1	508,767	(444,303)	(4,168)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock—option exercise (in shares)		80,000
Issuance of common stock—option exercise	112		112
Issuance of common stock—restricted stock (in shares)		2,195,104
Compensation expense related to issued stock options and restricted stock awards	911		911
Net loss	(14,057)			(14,057)
Other comprehensive income (loss)	1,906				1,906
Ending balance (in shares) at Jun. 30, 2018		63,113,630
Ending balance at Jun. 30, 2018	$ 49,169	$ 1	509,790	(458,360)	(2,262)
Beginning balance (in shares) at Dec. 31, 2018	65,290,879	65,290,879
Beginning balance at Dec. 31, 2018	$ 36,200	$ 1	513,336	(475,667)	(1,470)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock—option exercise (in shares)		34,669
Issuance of common stock—option exercise	121		121
Issuance of common stock—restricted stock (in shares)		2,588,450
Issuance of common stock - Innovatus (in shares)		775,194
Issuance of common stock	3,000		3,000
Compensation expense related to issued stock options and restricted stock awards	2,106		2,106
Net loss	(14,344)			(14,344)
Other comprehensive income (loss)	$ 218				218
Ending balance (in shares) at Jun. 30, 2019	68,689,192	68,689,192
Ending balance at Jun. 30, 2019	$ 27,301	$ 1	518,563	(490,011)	(1,252)
Beginning balance (in shares) at Mar. 31, 2019		67,880,664
Beginning balance at Mar. 31, 2019	30,387	$ 1	514,484	(483,248)	(850)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock—option exercise (in shares)		34,669
Issuance of common stock—option exercise	121		121
Issuance of common stock—restricted stock (in shares)		1,335
Issuance of common stock - Innovatus (in shares)		775,194
Issuance of common stock	3,000		3,000
Compensation expense related to issued stock options and restricted stock awards	958		958
Net loss	(6,763)			(6,763)
Other comprehensive income (loss)	$ (402)				(402)
Ending balance (in shares) at Jun. 30, 2019	68,689,192	68,689,192
Ending balance at Jun. 30, 2019	$ 27,301	$ 1	$ 518,563	$ (490,011)	$ (1,252)