Stock Warrants - Additional Information (Detail) (Common Stock Warrant [Member])	Dec. 31, 2013	Dec. 31, 2012
Common Stock Warrant [Member]
Class of Warrant or Right [Line Items]
Number of warrants cashless exercised	65,000	100,000
Number of common stock issued as a result of cashless exercise of warrants	35,000	71,000

The number of shares of common stock issued during the period as a result of the cashless exercise of warrants.

No definition available.

Name:	mack_CommonStockSharesIssuedCashless
Namespace Prefix:	mack_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	instant