Leases - Supplemental Cash Flows (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 USD ($)
Cash paid for amounts included in the measurement of lease liabilities:
Operating cash flows from operating leases	$ 35
Operating cash flows from financing leases	1
Financing cash flows from finance leases	10
Operating lease right-of-use assets obtained in exchange for new operating lease liabilities	21
Right-of-use assets obtained in exchange for new finance lease liabilities	$ 0