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	Mar. 31, 2020	Dec. 31, 2019
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	$ 62,011	$ 2,993
12 Months or more Unrealized Losses	2,056	168
Total Unrealized Losses	64,067	3,161
Less than 12 months Fair Value	128,574	55,314
12 Months or more Fair Value	1,664	821
Total Fair Value	130,238	56,135
Fixed maturities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	110	30
12 Months or more Unrealized Losses	206	168
Total Unrealized Losses	316	198
Less than 12 months Fair Value	5,847	288
12 Months or more Fair Value	759	821
Total Fair Value	6,606	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	82	64
Total Unrealized Losses	82	65
Less than 12 months Fair Value		90
12 Months or more Fair Value	302	397
Total Fair Value	302	487
Fixed maturities | Corporate debt securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	110	29
12 Months or more Unrealized Losses	124	104
Total Unrealized Losses	234	133
Less than 12 months Fair Value	5,847	198
12 Months or more Fair Value	457	424
Total Fair Value	6,304	622
Mutual funds - debt securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	2,064	6
12 Months or more Unrealized Losses	400
Total Unrealized Losses	2,464	6
Less than 12 months Fair Value	19,756	241
Total Fair Value	19,756	241
Mutual funds - equity securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	23,880
12 Months or more Unrealized Losses	1,356
Total Unrealized Losses	25,236
Less than 12 months Fair Value	18,857
Total Fair Value	18,857
Other investment funds
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	15,626	2,953
Total Unrealized Losses	15,626	2,953
Less than 12 months Fair Value	59,261	54,782
Total Fair Value	59,261	54,782
Equity securities
Investments, Unrealized Loss Position [Line Items]
Less than 12 months Unrealized Losses	20,331	4
Total Unrealized Losses	20,331	4
Less than 12 months Fair Value	24,853	3
Total Fair Value	24,853	$ 3
Other invested assets
Investments, Unrealized Loss Position [Line Items]
12 Months or more Unrealized Losses	94
Total Unrealized Losses	94
12 Months or more Fair Value	905
Total Fair Value	$ 905