Long-Term Debt (Debt Borrowings)(Details) - USD ($) $ in Millions	Jun. 30, 2017	Mar. 31, 2017	Jan. 31, 2017
Floating Rate Notes Due 2021 [Member]
Debt Instrument [Line Items]
Debt face amount	$ 1,500
Senior 4.45% Notes Due 2047 [Member]
Debt Instrument [Line Items]
Debt face amount		$ 1,005
Interest rate		4.45%
Senior 3.0% Notes Due 2024 [Member]
Debt Instrument [Line Items]
Debt face amount			$ 1,250
Interest rate			3.00%
Senior 3.3% Notes Due 2027 [Member]
Debt Instrument [Line Items]
Debt face amount			$ 1,250
Interest rate			3.30%