MERCHANDISE TRUSTS - Aging of Unrealized Losses on Investments in Fixed Maturities and Equity Securities Held in Merchandise Trusts (Detail) - Variable Interest Entity, Primary Beneficiary - Merchandise Trusts - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	$ 41,976	$ 2,993
12 Months or more Unrealized Losses	1,923	168
Total Unrealized Losses	43,899	3,161
Less than 12 months Fair Value	175,391	55,314
12 Months or more Fair Value	803	821
Total Fair Value	176,194	56,135
Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	15	30
12 Months or more Unrealized Losses	192	168
Total Unrealized Losses	207	198
Less than 12 months Fair Value	8,890	288
12 Months or more Fair Value	803	821
Total Fair Value	9,693	1,109
Fixed maturities | U.S. governmental securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses		1
12 Months or more Unrealized Losses	72	64
Total Unrealized Losses	72	65
Less than 12 months Fair Value	29	90
12 Months or more Fair Value	300	397
Total Fair Value	329	487
Fixed maturities | Corporate debt securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	6	29
12 Months or more Unrealized Losses	120	104
Total Unrealized Losses	126	133
Less than 12 months Fair Value	2,087	198
12 Months or more Fair Value	503	424
Total Fair Value	2,590	622
Fixed maturities | Other Debt Securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	9
Total Unrealized Losses	9
Less than 12 months Fair Value	6,774
Total Fair Value	6,774
Mutual funds - debt securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	472	6
12 Months or more Unrealized Losses	348
Total Unrealized Losses	820	6
Less than 12 months Fair Value	11,436	241
Total Fair Value	11,436	241
Mutual funds - equity securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	15,900
12 Months or more Unrealized Losses	1,383
Total Unrealized Losses	17,283
Less than 12 months Fair Value	25,533
Total Fair Value	25,533
Other investment funds
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	13,618	2,953
Total Unrealized Losses	13,618	2,953
Less than 12 months Fair Value	99,890	54,782
Total Fair Value	99,890	54,782
Equity securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	11,971	4
Total Unrealized Losses	11,971	4
Less than 12 months Fair Value	29,642	3
Total Fair Value	$ 29,642	$ 3