Share-based Compensation (Details 1) (USD $) In Thousands, unless otherwise specified	9 Months Ended
Sep. 30, 2012
Share-based compensation expense outstanding unvested options to be recognized
Fiscal Year 2012 (October 1, 2012 to December 31, 2012)	$ 311
Fiscal Year 2013	980
Fiscal Year 2014	504
Fiscal Year 2015	216
Thereafter	85
Share based compensation expense expected to be recognized	$ 2,096

Share-based compensation expense expected to be recognized

No definition available.

Name:	vrnm_ShareBasedCompensationExpenseExpectedToBeRecognized
Namespace Prefix:	vrnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Share-based compensation expense expected to be recognized after year four.

No definition available.

Name:	vrnm_ShareBasedCompensationExpenseExpectedToBeRecognizedAfterYearFour
Namespace Prefix:	vrnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Share-based compensation expense expected to be recognized next twelve months.

No definition available.

Name:	vrnm_ShareBasedCompensationExpenseExpectedToBeRecognizedNextTwelveMonths
Namespace Prefix:	vrnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Share-based compensation expense expected to be recognized year four.

No definition available.

Name:	vrnm_ShareBasedCompensationExpenseExpectedToBeRecognizedYearFour
Namespace Prefix:	vrnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Share-based compensation expense expected to be recognized year three.

No definition available.

Name:	vrnm_ShareBasedCompensationExpenseExpectedToBeRecognizedYearThree
Namespace Prefix:	vrnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Share-based compensation expense expected to be recognized year two.

No definition available.

Name:	vrnm_ShareBasedCompensationExpenseExpectedToBeRecognizedYearTwo
Namespace Prefix:	vrnm_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Name:	vrnm_ShareBasedCompensationExpenseOutstandingUnvestedOptionsToBeRecognizedAbstract
Namespace Prefix:	vrnm_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration