Weighted Average Assumptions Used to Calculate Fair Value of Options Granted (Parenthetical) (Detail)	12 Months Ended
	Dec. 31, 2013 Y	Dec. 31, 2012 Y	Dec. 31, 2011 Y
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected life of new grants issued	2.58	4.00	4.25
Expected life of options assumed in acquisitions	Less than 4 years