Borrowings and Lines of Credit Borrowings and lines of Credit (Second Quarter Actions) (Details) - 3 months ended Jun. 30, 2015 € in Millions, shares in Millions, $ in Millions	USD ($) shares	EUR (€) shares
1.550% junior subordinated notes due 2022 [Member]
Debt Instrument [Line Items]
Remarketing of Debt Instrument, Date	May 04, 2015	May 04, 2015
Notes 4.150% Due 2045 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt	$ 850
Debt Instrument, Issuance Date	May 04, 2015	May 04, 2015
Notes 4.875% Due 2015 [Member]
Debt Instrument [Line Items]
Repayment of Debt, Date	May 01, 2015	May 01, 2015
Repayments of Debt	$ 1,200
LIBOR Plus 0.500% Floating Rate Notes Due 2015 [Member]
Debt Instrument [Line Items]
Repayment of Debt, Date	Jun. 01, 2015	Jun. 01, 2015
Repayments of Debt	$ 500
Junior subordinated notes 1.778% due 2018 [Member]
Debt Instrument [Line Items]
Long Term Debt Remarketing, Expected Proceeds	$ 1,100
Remarketing of Long Term Debt, Date Proceeds Received	Aug. 03, 2015	Aug. 03, 2015
Long Term Debt Remarketing, Number of Shares Issued | shares	11.3	11.3
Notes 1.250% due 2023 [Member]
Debt Instrument [Line Items]
Proceeds from Issuance of Debt | €		€ 750
Debt Instrument, Issuance Date	May 22, 2015	May 22, 2015