New Accounting Standards Recently Adopted Accounting Pronouncements (Details) - USD ($) $ in Millions	3 Months Ended
	Dec. 31, 2017	Jun. 30, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Deferred tax asset from stock options exercised and restricted stock vestings	$ 179
Minimum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Description		10.00%
Maximum [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
New Accounting Pronouncement or Change in Accounting Principle, Description		15.00%