Revenue Arrangements - Schedule of Changes in Contract Liabilities (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2020 USD ($)
Contract liabilities:
Deferred revenue, beginning of period	$ 16,354
Contract liabilities, beginning of period	16,354
Deferred revenue, additions	0
Contract liabilities, additions	0
Deferred revenue, deductions	(24)
Contract liabilities, deductions	(24)
Deferred revenue, end of period	16,330
Contract liabilities, end of period	$ 16,330