Effects of Derivative Instruments on Financial Statements (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Amount of gain recognized in other comprehensive income attributable to MII	$ 1,576	$ 4,505
Cost of operations
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Income reclassified from AOCI into income: effective portion attributable to MII	6,213	430
Gain (loss) on foreign currency - net
Derivative Instruments and Hedging Activities Disclosure [Line Items]
Gain recognized in income: ineffective portion and amount excluded from effectiveness testing attributable to MII	$ 23,116	$ 2,516