Commitments and Contingencies (Narrative) (Detail)	3 Months Ended
	Jun. 30, 2019 Lawsuits
Commitments And Contingencies [Line Items]
Other material lawsuits pending	0
PREPA minimum settlement percentage	60.00%
PREPA Bondholders in RSA	72.00%
With Syncora [Member]
Commitments And Contingencies [Line Items]
PREPA Bondholders in RSA	74.00%