Recent Accounting Guidance Lease ASU - Effect on Balance Sheet (Details) - Scenario, Forecast [Member] - Accounting Standards Update 2016-02 [Member] $ in Millions	Dec. 31, 2018 USD ($)
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset	$ 600
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating Lease, Right-of-Use Asset	$ 800