Stockholders' Equity , Share Repurchase Program (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019	Jan. 31, 2016
Share Repurchase Program [Line Items]
Stock repurchased in the period, value	$ 899,900,000	$ 56,200,000
Repurchase Program [Member]
Share Repurchase Program [Line Items]
Stock repurchase program, authorized amount			$ 2,500,000,000
Stock repurchased in the period, shares	10.0
Stock repurchased, average price (in dollars per share)	$ 90.36
Stock repurchased in the period, value	$ 899,900,000
Stock repurchase program, unused balance	$ 692,900,000