Restructuring and Other Items - Summary of Significant Activity Within, and Components of Restructuring Obligations (Parenthetical) (Detail)	3 Months Ended
	Mar. 31, 2013
Employee severance and benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities, Completion Date	Dec. 31, 2013
Lease terminations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and Related Activities, Completion Date	Dec. 31, 2014