Weighted-Average Shares Outstanding for Computation of Basic and Diluted Income Per Common Share (Detail)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Earnings Per Share [Abstract]
Basic method	181,367,565	190,810,201	[1]
Dilutive stock options and restricted stock units	1,209,005	955,194
Diluted method	182,576,570	191,765,395	[1]

[1] Reclassified to conform to current presentation.