Reinsurance - Summary of Quota Reinsurance Arrangements (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Effects of Reinsurance [Line Items]
Ceded losses incurred	$ (508)	$ 5,469	$ 3,810	$ 14,486
Quota Share Reinsurance Agreements, Excluding Captive Agreements
Effects of Reinsurance [Line Items]
Ceded premiums written and earned, net of profit commission	25,248	30,880	79,716	88,692
Ceded losses incurred	(522)	5,879	3,531	14,990
Ceding commissions	12,983	12,500	38,268	36,751
Profit commission	$ 39,664	$ 31,621	$ 111,622	$ 95,063

Ceded Premiums Written and Earned, Net of Profit Commission

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- Definition

Reinsurance, Profit Commission

+ References

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Amount of fees and commissions from financial services and banking activities and correspondent clearing. Includes fees from depositor accounts, credit cards, merchant discounts, and fiduciary and trust activities, guarantee fees, investment advisory, management, and administrative fees, transfer agent fees, and insurance commissions.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 225
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-04.13)
-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

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- Definition

Amount of reduction of provision for policy benefits and costs incurred for policies ceded.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 20
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6480758&loc=d3e6811-158387

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