Segment and Geographic Information - Summary of Accounts Receivable Derived from Customers (Parenthetical) (Detail)	Mar. 31, 2015	Mar. 31, 2014
Segment Reporting [Abstract]
Percentage of accounts receivable from major customers	10.00%	10.00%

Percentage of accounts receivable major customers.

No definition available.

Name:	bzc_PercentageOfAccountsReceivableMajorCustomers
Namespace Prefix:	bzc_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant