Variable Interest Entities - Assets and Liabilities Related to VIEs that are Not Consolidated (Detail) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Maximum risk of loss as a result of the Company’s involvement with VIEs:
Income and fees receivable	$ 215,395	$ 82,843
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Net assets of unconsolidated VIEs in which the Company has a variable interest	8,805,128	10,236,438
Maximum risk of loss as a result of the Company’s involvement with VIEs:
Unearned revenues	63,337	62,038
Income and fees receivable	21,841	31,658
Investments	200,215	190,674
Maximum Exposure to Loss	$ 285,393	$ 284,370