Long-Lived Assets - Schedule of Accretion Discount Rates on Interest Method (Detail)	1 Months Ended				9 Months Ended		12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2014
Property, Plant and Equipment [Abstract]
Accretion discount rates on interest method	12.10%	10.48%	10.60%	12.14%	10.60%	10.77%	10.48%