PERPETUAL CARE TRUSTS - Cost and Market Value Associated with Assets Held in Perpetual Care Trusts (Parenthetical) (Detail) - Perpetual care trusts - Variable Interest Entity, Primary Beneficiary $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2021 USD ($) Extension	Dec. 31, 2020 USD ($) Extension
Debt Securities, Available-for-sale [Line Items]
Number of potential lockup period extensions | Extension	3	3
Lockup extension period	1 year	1 year
Unfunded investment commitments to private credit funds, callable at any time | $	$ 72.5	$ 41.1
Minimum
Debt Securities, Available-for-sale [Line Items]
Fixed income funds and equity funds, redemption period	1 day	1 day
Private credit funds, lockup periods	0 years	0 years
Maximum
Debt Securities, Available-for-sale [Line Items]
Fixed income funds and equity funds, redemption period	30 days	30 days
Private credit funds, lockup periods	15 years	6 years