Leases (Textuals) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Jan. 01, 2019
Lessor, Lease, Description [Line Items]
Operating liability, current	$ 61
Operating liability, noncurrent	185
Right-of-use assets	241			$ 267
Revenue from lease arrangements	247
Assets subject to rental	256
Assets subject to rental, accumulated amortization	166
Operating Leases, Rent Expense		$ 81	$ 70
Depreciation	117	$ 117	$ 109
Leased Assets
Lessor, Lease, Description [Line Items]
Depreciation	$ 28