Revenue Arrangements - Schedule of Changes in Contract Liabilities (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2020 USD ($)
Contract liabilities:
Deferred revenue, beginning of period	$ 16,354
Contract liabilities, beginning of period	16,354
Deferred revenue, additions	2,000
Contract liabilities, additions	2,000
Deferred revenue, deductions	(14)
Contract liabilities, deductions	(14)
Deferred revenue, end of period	18,340
Contract liabilities, end of period	$ 18,340