Commitments and Contingencies - Narrative (Detail)		12 Months Ended
	Oct. 15, 2020 USD ($) consumer	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)
Loss Contingencies [Line Items]
Material reserves for legal matters		$ 0
Purchase price		157,400,000
Estimated fair value, liability		0
401(K) Expense Recognized		2,900,000	$ 2,800,000	$ 2,500,000
CFPB Stipulated Judgement
Loss Contingencies [Line Items]
Litigation settlement, amount awarded to other party	$ 15,000,000.0
Litigation settlement, amount of redress awarded to affected consumers	$ 9,000
Litigation settlement, number of affected consumers | consumer	14
Litigation settlement, amount of redress previously voluntarily paid	$ 70,000
Litigation Settlement, Expense		$ 15,000,000.0