Reserve For Unpaid Losses - Summary of Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	$ 2,885,186
2016 & prior
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	254,032	$ 252,212	$ 249,901	$ 246,826	$ 244,820	$ 241,875	$ 238,868	$ 233,540	$ 211,512	$ 132,679
2017
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	264,544	244,841	163,068	194,079	188,928	184,313	178,622	168,606	$ 101,541
2018
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	290,230	288,794	285,447	277,489	265,868	248,783	232,211	$ 164,641
2019
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	180,718	177,816	172,497	161,938	147,406	125,359	$ 64,356
2021
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	360,416	351,397	334,937	324,860	299,825	$ 198,834
2022
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	352,707	345,419	329,367	302,379	$ 215,478
2022
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	394,456	380,005	339,825	$ 224,721
2023
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	313,696	291,089	$ 191,596
2024
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	305,670	$ 228,670
2025
Claims Development [Line Items]
Cumulative Paid Losses and Allocated Loss Adjustment Expenses, Net of Reinsurance	$ 168,716

Heritage Insurance Holdings, Inc. 10-K