Shareholders' Equity - Treasury Stock (Details) - Treasury Stock - USD ($) shares in Thousands	5 Months Ended	7 Months Ended	12 Months Ended
	Dec. 31, 2019	Jul. 31, 2019	Dec. 31, 2019	Dec. 31, 2018	Jun. 30, 2019
Schedule of Common Stock and Treasury Stock [Line Items]
Authorized share repurchase program	$ 1,000,000,000	$ 2,000,000,000	$ 1,000,000,000
Stock repurchase program, remaining authorized repurchase amount	700,000,000		$ 700,000,000
Share repurchase cost	300,000,000	1,000,000,000
Share repurchase fees	$ 0	$ 1,000,000
Number of shares repurchased	9,097	35,339	18,343	26,093
July 2019 Share Repurchase Plan
Schedule of Common Stock and Treasury Stock [Line Items]
Authorized share repurchase program		$ 1,000,000,000.0
Previous Share Repurchase Program
Schedule of Common Stock and Treasury Stock [Line Items]
Stock repurchase program, remaining authorized repurchase amount					$ 1,000,000,000.0