Revenue Arrangements - Schedule of Changes in Contract Liabilities (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019 USD ($)
Contract liabilities:
Deferred revenue, beginning of period	$ 14,777
Other liabilities, beginning of period	2,126
Contract liabilities, beginning of period	16,903
Deferred revenue, additions	8,254
Other liabilities, additions	0
Contract liabilities, additions	8,254
Deferred revenue, deductions	(6,677)
Other liabilities, deductions	(2,126)
Contract liabilities, deductions	(8,803)
Deferred revenue, end of period	16,354
Other liabilities, end of period	0
Contract liabilities, end of period	$ 16,354