CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOW - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Cash Flows From Operating Activities:
Net Loss	$ (134,538)	$ (62,827)
Adjustments to Reconcile Net Loss to Net Cash Used in Operating Activities:
Depreciation and Amortization	2,021	2,367
Amortization of Intangible Assets	224	448
Amortization and Premium of Marketable Securities, Net	(380)	(161)
Loss on Sale or Disposal of Assets	1,069
Goodwill Impairment	90,976
Intangible Asset Impairment	18,677
(Gain)/Loss on Fair Value Remeasurement of Contingent Consideration	(21,033)	4,400
Non-Cash Income Tax Benefit	(765)
Stock-Based Compensation Expense	4,536	6,989
Changes in Operating Assets and Liabilities:
Accounts and Other Receivables	(713)	425
Prepaid and Other Current Assets	801	(511)
Other Assets		199
Accounts Payable and Accrued Expenses	(5,895)	(6,812)
Other Liabilities	(397)	(566)
Net Cash Used in Operating Activities	(45,417)	(56,049)
Cash Flows From Investing Activities:
Sales and Maturities of Marketable Securities	106,182	151,470
Purchases of Marketable Securities	(76,902)	(91,969)
Acquisition of Property and Equipment	(591)	(1,316)
Net Cash Provided by Investing Activities	28,689	58,185
Cash Flows From Financing Activities:
Net Proceeds from Stock Issuances	19,960	21,489
Proceeds from Issuance of Stock from Employee Benefit Plans	374	76
Net Cash Provided by Financing Activities	20,334	21,565
Net Increase in Cash and Cash Equivalents	3,606	23,701
Cash and Cash Equivalents at Beginning of Period	40,288	42,461
Cash and Cash Equivalents at End of Period	43,894	66,162
Non-cash Investing Activities
Accrued construction in progress		87
Non-cash Supplemental Disclosure
Shares issued to former Kolltan executive for settlement of severance	$ 57	$ 263