Derivatives and Hedging - Foreign Hedge (Details) - 6 months ended Jun. 30, 2018 - Net Investment Hedging € in Millions, $ in Millions	USD ($)	EUR (€)
Derivatives, Fair Value
European denominated commercial paper	$ 256	€ 220
Effective portion of loss reclassified from Accumulated OCI	$ 15

Amount before tax and reclassification adjustments of gain (loss) on foreign currency translation adjustments, foreign currency transactions designated and effective as economic hedges of a net investment in a foreign entity and intra-entity foreign currency transactions that are of a long-term-investment nature.

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