Significant Accounting Policies and Pronouncements (Narrative) (Details) - USD ($) $ in Millions	Jun. 30, 2019	Jan. 01, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset	$ 561
Operating Lease, Liability	$ 589
ASU 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset		$ 600
Operating Lease, Liability		$ 600