Subsequent Events (Details) - Subsequent Event - USD ($) $ in Billions	1 Months Ended
Mar. 31, 2019	Feb. 28, 2019
Subsequent Event
Purchase of UPB of Ginnie Mae MSRs	$ 11.9
Letter of Intent
Subsequent Event
Purchase of UPB of Ginnie Mae MSRs		$ 4.5

Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event.

No definition available.

Name:	us-gaap_SubsequentEventLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration