Acquisitions Acquisitions (narrative) (Details) - USD ($) $ in Millions		6 Months Ended
	Jul. 13, 2020	Jun. 30, 2020	Jun. 30, 2019
Business Acquisition [Line Items]
Payments for Other Deposits		$ 1,550	$ 0
CHINA | Huatai Group [Member]
Business Acquisition [Line Items]
Payments for Other Deposits		$ 1,550
CHINA | Huatai Group [Member] | Subsequent Event [Member]
Business Acquisition [Line Items]
Equity method investment, additional 15.3 ownership percentage obtained	15.30%