Subsequent Events (Details) $ / shares in Units, $ in Millions	Aug. 04, 2021 USD ($) $ / shares	Aug. 01, 2021	Jul. 30, 2021 USD ($) item	Feb. 28, 2021 USD ($)	Jun. 30, 2017 USD ($)
Securities Repurchase Agreements
Authorized stock repurchase amount				$ 1,000
Common Stock
Securities Repurchase Agreements
Authorized stock repurchase amount				$ 1,000	$ 500
Subsequent Event
Subsequent Event
Dividends declared (in dollars per share) | $ / shares	$ 0.20
Adverse market refinance fee percent eliminated		0.50%
Securities Repurchase Agreements
Authorized stock repurchase amount	$ 2,000
Subsequent Event | Syndicated Repurchase Agreement
Subsequent Event
Number of indirect wholly owned subsidiaries entered into agreements | item			2
The number of existing variable funding note repurchase agreements | item			2
Securities Repurchase Agreements
Previous maximum aggregate purchase price			$ 400
Maximum aggregate purchase price			500
Subsequent Event | Syndicated Repurchase Agreement SAR
Securities Repurchase Agreements
Maximum aggregate purchase price			$ 600