Summary of Significant Accounting Policies (Details) $ in Millions	Dec. 31, 2018 USD ($)
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	$ 130
Operating lease liabilities	120
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	160
Operating lease liabilities	$ 150