Shareholders' Equity (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Nov. 02, 2016
Equity, Class of Treasury Stock [Line Items]
Stock repurchased during period (in shares)			0	0
Dividends declared per share (in dollars per share)	$ 0.50	$ 0.5	$ 1.50	$ 1.5
2016 Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount					$ 15,000,000,000.0
Stock repurchase program, remaining authorized repurchase amount	$ 13,900,000,000		$ 13,900,000,000