Leases - Lease Assets and Liabilities (Details) $ in Millions	Jun. 30, 2019 USD ($)
Assets:
Operating lease assets	$ 681
Finance lease assets	19
Total lease assets	700
Liabilities:
Current lease liabilities	252
Lease liabilities	445
Total lease liabilities	697
Current lease liabilities
Liabilities:
Current lease liabilities	242
Finance, liability, current	10
Deferred credits and other liabilities - Lease liabilities
Liabilities:
Lease liabilities	437
Finance, liability, noncurrent	$ 8