Commitments, Guarantees and Contingencies - Additional Information (Details) - USD ($) $ in Thousands		9 Months Ended
May 10, 2018	Dec. 31, 2018
Disclosure Of Commitments And Contingencies [Line Items]
Applicable program documentation period		365 days
Federal Securities Class Action
Disclosure Of Commitments And Contingencies [Line Items]
Amount payable under settlement agreement	$ 19,000

Amount awarded to other party in judgment or settlement of litigation.

No definition available.

Name:	us-gaap_LitigationSettlementAmountAwardedToOtherParty
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration