Leases - Adoption of ASC 842 (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease, operating lease, terminate term	1 year
Finance lease	$ 0	$ 0
Maximum
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease, term of contract	12 months