Liability for Unpaid Losses and Loss Adjustment Expense Liability for Unpaid Losses and Loss Adjustment Expense - Reconciliation (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Reinsurance Recoverables on Unpaid Losses	$ 18,724	$ 2,114
Short-duration Insurance Contracts, Liability for Unpaid Claims and Claims Adjustment Expense, Accumulated Unallocated Claim Adjustment Expense	6,214
Unpaid losses and loss adjustment expenses	140,855	$ 76,792	$ 54,436	$ 47,451
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net	115,917
Homeowners' Insurance Product
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Reinsurance Recoverables on Unpaid Losses	14,223
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net	109,320
Other Short-duration Insurance Product Line
Short-duration Insurance Contracts, Reconciliation of Claims Development to Liability [Line Items]
Reinsurance Recoverables on Unpaid Losses	4,501
Short-duration Insurance Contracts, Liability for Unpaid Claims and Allocated Claim Adjustment Expense, Net	$ 6,597