Leases - Schedule of Future Sublease Income Term (Detail) $ in Thousands	Jun. 30, 2019 USD ($)
Leases [Abstract]
2019 (6 months remaining)	$ 1,258
2020	2,563
2021	2,628
2022	2,695
2023	2,764
Thereafter	2,355
Total	$ 14,263

Operating leases future minimum payments receivable sublease rentals due.

No definition available.

Name:	arav_OperatingLeasesFutureMinimumPaymentsReceivableSubleaseRentalsDue
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Operating leases future minimum payments receivable sublease rentals in five years.

No definition available.

Name:	arav_OperatingLeasesFutureMinimumPaymentsReceivableSubleaseRentalsInFiveYears
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Operating leases future minimum payments receivable sublease rentals in four years.

No definition available.

Name:	arav_OperatingLeasesFutureMinimumPaymentsReceivableSubleaseRentalsInFourYears
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Operating leases future minimum payments receivable sublease rentals in three years.

No definition available.

Name:	arav_OperatingLeasesFutureMinimumPaymentsReceivableSubleaseRentalsInThreeYears
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Operating leases future minimum payments receivable sublease rentals in two years.

No definition available.

Name:	arav_OperatingLeasesFutureMinimumPaymentsReceivableSubleaseRentalsInTwoYears
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Operating leases future minimum payments receivable sublease rentals remainder of fiscal year.

No definition available.

Name:	arav_OperatingLeasesFutureMinimumPaymentsReceivableSubleaseRentalsRemainderOfFiscalYear
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

Operating leases future minimum payments receivable sublease rentals thereafter.

No definition available.

Name:	arav_OperatingLeasesFutureMinimumPaymentsReceivableSubleaseRentalsThereafter
Namespace Prefix:	arav_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

No definition available.