Statements of Cash Flows (unaudited) (Parenthetical) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Mar. 31, 2011
Statement of Cash Flows [Abstract]
Cash and cash equivalents from discontinued operations	$ 7,396	$ 8,459

Cash and Cash Equivalents From Discontinued Operations, at Carrying Value

No definition available.

Name:	mrvc_CashAndCashEquivalentsFromDiscontinuedOperationsAtCarryingValue
Namespace Prefix:	mrvc_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant