Acquisition and Discontinued Operations - Discontinued Operations (Details) $ in Thousands	3 Months Ended				9 Months Ended		12 Months Ended
	Mar. 31, 2020 USD ($)	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($) claim	Sep. 30, 2018 USD ($)	Sep. 30, 2019 USD ($)	Sep. 30, 2018 USD ($)	Dec. 31, 2018 USD ($)	Dec. 31, 2019 USD ($)	Oct. 18, 2018 USD ($)	Jun. 30, 2018 USD ($)	Apr. 01, 2015
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposal of discontinued operations, net of taxes		$ 0		$ (1,172)	$ 0	$ (7,800)
Final aggregate purchase price										$ 1,700
Mendota
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposal of discontinued operations, net of taxes				$ (1,200)		$ (9,100)	$ (8,500)
Final aggregate purchase price									$ 28,600
Escrow deposit									$ 5,000
Maximum obligation		$ 2,500			$ 2,500
Number of claims settled | claim			1
Indemnification claim settled			$ 500
Mendota | Forecast
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Estimated net loss								$ 1,600
Released escrow deposit	$ 3,400
Discontinued Operations
Income Statement, Balance Sheet and Additional Disclosures by Disposal Groups, Including Discontinued Operations [Line Items]
Gain (loss) on disposal of discontinued operations, net of taxes							$ 1,300
Future earnout payments, as a percentage of written premium and fee income											1.25%