Leases - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Lessee, Lease, Description [Line Items]
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 46	$ 67
Term of contract	14 years
Office space | Arizona
Lessee, Lease, Description [Line Items]
Right-of-use assets obtained in exchange for new operating lease liabilities	$ 19