Commitments and Contingencies - Additional Information (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Other Commitments [Line Items]
Reinsurance payable, net	$ 93,306	$ 110,381
June 1 2019 - May 31 2020
Other Commitments [Line Items]
Reinsurance payable, net	82,300
June 1 2020 - May 31 2021
Other Commitments [Line Items]
Reinsurance payable, net	$ 33,900

The carrying amount as of the balance sheet date of the known and estimated amounts owed to insurers under reinsurance treaties or other arrangements.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03.13(a)(3),(c))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Name:	us-gaap_ReinsurancePayable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant