Acquired Card Receivables - Summary of Fair Value of Consideration Received from Transfer of Card Receivables (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Mar. 31, 2022	Mar. 31, 2022
Acquired Card Receivables [Abstract]
Cash	$ 394,497	$ 1,019,704
Beneficial interest derivative	1,100	3,387
Total	$ 395,597	$ 1,023,091

Initial fair value of consideration received beneficial interest derivative.

No definition available.

Name:	bill_InitialFairValueOfConsiderationReceivedBeneficialInterestDerivative
Namespace Prefix:	bill_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration