INVESTMENTS - Gross Unrealized Losses and Fair Value by Length of Time of Available-For-Sale Securities (Detail) $ in Thousands	Dec. 31, 2021 USD ($) security	Dec. 31, 2020 USD ($) security
Debt Securities, Available-for-sale [Line Items]
Number of Securities | security	141	34
Fair Value
Less Than 12 Months	$ 778,714	$ 92,868
12 Months or More	59,597	76,879
Total	838,311	169,747
Unrealized Losses
Less Than 12 Months	12,583	367
12 Months or More	2,837	693
Total	$ 15,420	$ 1,060
U.S. treasuries and government agencies
Debt Securities, Available-for-sale [Line Items]
Number of Securities | security	5	2
Fair Value
Less Than 12 Months	$ 49,695	$ 25,369
12 Months or More	0	0
Total	49,695	25,369
Unrealized Losses
Less Than 12 Months	150	2
12 Months or More	0	0
Total	$ 150	$ 2
State and municipal
Debt Securities, Available-for-sale [Line Items]
Number of Securities | security	32	8
Fair Value
Less Than 12 Months	$ 63,206	$ 22,753
12 Months or More	21,740	0
Total	84,946	22,753
Unrealized Losses
Less Than 12 Months	2,288	211
12 Months or More	1,157	0
Total	$ 3,445	$ 211
Mortgage-backed and asset-backed
Debt Securities, Available-for-sale [Line Items]
Number of Securities | security	104	24
Fair Value
Less Than 12 Months	$ 665,813	$ 44,746
12 Months or More	37,857	76,879
Total	703,670	121,625
Unrealized Losses
Less Than 12 Months	10,145	154
12 Months or More	1,680	693
Total	$ 11,825	$ 847