Variable Interest Entities - Assets and Liabilities Related to VIEs that are Not Consolidated (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Maximum risk of loss as a result of the Company’s involvement with VIEs:
Income and fees receivable	$ 43,782	$ 215,395
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Net assets of unconsolidated VIEs in which the Company has a variable interest	8,215,166	8,805,128
Maximum risk of loss as a result of the Company’s involvement with VIEs:
Unearned revenues	64,900	63,337
Income and fees receivable	26,811	21,841
Investments	173,137	200,215
Maximum Exposure to Loss	$ 264,848	$ 285,393