Notes Receivable and Allowance for Credit Losses - Narrative (Details)	12 Months Ended
Dec. 31, 2023
Receivables [Abstract]
Weighted average days outstanding of notes receivable	34 days

Financing Receivable, Excluding Accrued Interest, Weighted Average Days Outstanding

No definition available.

Name:	szl_FinancingReceivableExcludingAccruedInterestWeightedAverageDaysOutstanding
Namespace Prefix:	szl_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration