Stock-Based Compensation - Summary of Stock Options (Detail) (Stock Options [Member], USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Outstanding shares, beginning of year	12,997
Granted, shares	1,968
Exercised, shares	(4,788)
Forfeited or expired, shares	(503)
Outstanding shares, end of year	9,674
Exercisable shares, end of year	3,790
Outstanding, Weighted Average Exercise Price, beginning of year	$ 33.96
Granted, Weighted Average Exercise Price	$ 36.93
Exercised, Weighted Average Exercise Price	$ 31.06
Forfeited or expired, Weighted Average Exercise Price	$ 34.32
Outstanding, Weighted Average Exercise Price, end of year	$ 35.98
Exercisable, Weighted Average Exercise Price, end of year	$ 35.01