Equity - Stock Repurchase Activities (Details) - USD ($) $ / shares in Units, shares in Millions	3 Months Ended			9 Months Ended
	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018	Sep. 30, 2018	Feb. 28, 2018	Jan. 31, 2018
Accelerated Share Repurchases [Line Items]
Payment to repurchase stock	$ 2,900,000		$ 754,200,000
Stock Repurchase Program 2018
Accelerated Share Repurchases [Line Items]
Stock repurchase program, authorized amount						$ 2,000,000,000
Stock repurchased and retired (in shares)	0.0		23.3
Average price per share (in dollars per share)	$ 0.00		$ 25.80
Stock repurchase program, remaining authorized repurchase amount	$ 1,300,000,000
Accelerated Share Repurchase Program
Accelerated Share Repurchases [Line Items]
Stock repurchase program, authorized amount					$ 750,000,000
Payment to repurchase stock				$ 750,000,000
Stock repurchased and retired (in shares)	29.3	6.0	23.3
Average price per share (in dollars per share)	$ 25.62