Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Impairment Charge	$ 1,007	$ 500

Inventory Impairment, Results of Discounted Cash Flow Analysis

No definition available.

Name:	bzh_InventoryImpairmentResultsofDiscountedCashFlowAnalysis
Namespace Prefix:	bzh_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration