Stock Repurchases (Details) - USD ($) shares in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019	Dec. 13, 2019
Stock repurchase program, authorized amount			$ 3,000,000,000	$ 500,000,000
Stock repurchase program, remaining authorized amount	$ 446,000,000
Stock Repurchased During Period, Shares	0.4
Stock Repurchased During Period, Value	$ 100,000,000.0
Shares repurchased from employees who surrendered shares to satisfy minimum tax withholding obligations, value	$ 5,500,000	$ 13,500,000