Shareholders' Equity - Shares Repurchased (Details) - USD ($)	1 Months Ended	3 Months Ended						6 Months Ended		7 Months Ended	12 Months Ended
	Aug. 06, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Aug. 06, 2020	Dec. 31, 2019	Feb. 26, 2020
Equity, Class of Treasury Stock [Line Items]
Repurchases of common stock								$ 280,000,000	$ 190,000,000
Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Repurchase authorized amount												$ 250,000,000
Shares repurchased (in shares)		5,956,422	3,629,410	3,335,517	3,400,677	2,519,130	1,908,605				11,163,929
Repurchases of common stock		$ 164,000,000	$ 116,000,000	$ 160,000,000	$ 150,000,000	$ 111,000,000	$ 79,000,000				$ 500,000,000
Average price paid per share (in dollars per share)		$ 27.49	$ 32.03	$ 47.97	$ 44.11	$ 43.89	$ 41.62				$ 44.79
Subsequent Event [Member] | Common Stock [Member]
Equity, Class of Treasury Stock [Line Items]
Remaining capacity of shares repurchase program	$ 149,000,000									$ 149,000,000
Shares repurchased (in shares)	800,052									10,385,884
Repurchases of common stock	$ 19,000,000									$ 299,000,000
Average price paid per share (in dollars per share)	$ 23.17									$ 28.74