Stock-Based Compensation - Schedule of Unrecognized Compensation Cost (Details) $ in Thousands	Sep. 30, 2017 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
2017 (period from October 1 to December 31, 2017)	$ 850
2018	2,957
2019	2,031
2020	469
Total	$ 6,307

- Definition

Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options, Remainder of the Year

+ References

No definition available.

+ Details

Name:	buff_EmployeeServiceSharebasedCompensationNonvestedAwardsCompensationNotyetRecognizedStockOptionsRemainderoftheYear
Namespace Prefix:	buff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options, Year Four

+ References

No definition available.

+ Details

Name:	buff_EmployeeServiceSharebasedCompensationNonvestedAwardsCompensationNotyetRecognizedStockOptionsYearFour
Namespace Prefix:	buff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options, Year Three

+ References

No definition available.

+ Details

Name:	buff_EmployeeServiceSharebasedCompensationNonvestedAwardsCompensationNotyetRecognizedStockOptionsYearThree
Namespace Prefix:	buff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options, Year Two

+ References

No definition available.

+ Details

Name:	buff_EmployeeServiceSharebasedCompensationNonvestedAwardsCompensationNotyetRecognizedStockOptionsYearTwo
Namespace Prefix:	buff_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Unrecognized cost of unvested options awarded to employees as compensation.

+ References

No definition available.

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedStockOptions
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration