Contingencies, Commitments and Guarantees (Details) - Guarantees	Mar. 31, 2019 USD ($)
Indemnifications related to the sale of businesses [Member]
Guarantor obligations
Maximum amount of contingent obligation	$ 358,000,000
Guarantees of certain investments and third-party loans [Member]
Guarantor obligations
Maximum amount of contingent obligation	0
Guarantees of certain insurance policy obligations [Member]
Guarantor obligations
Maximum amount of contingent obligation	480,000,000
Amount indemnified by a third party	$ 480,000,000