Stockholders' Equity and Earnings Per Common Share - Additional Information (Detail) (USD $) In Millions, except Share data, unless otherwise specified	3 Months Ended		12 Months Ended
	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Stockholders Equity Note [Line Items]
Oustanding Stock Options, grant price range, lower limit			$ 11.37
Oustanding Stock Options, grant price range, upper limit			$ 26.29
Outstanding Nonvested stock awards, grant prices range, lower limit			$ 19.38
Outstanding Nonvested stock awards, grant prices range, upper limit			$ 32.35
Weighted Average Grant Date Fair Value of Shares Granted			$ 23.97
Antidilutive common shares not included in the computation of dilutive earnings per share			100,000	2,500,000	2,100,000
Shares Repurchased Cost Commissions			$ 0.2	$ 0.6	$ 0.3
Stock Repurchased During Period, Shares			11,200,000	23,600,000	25,400,000
Preferred stock, authorized			25,000,000
Preferred stock, par value			$ 0.10
Preferred stock, issued			0
Accelerated share repurchase program [Member]
Stockholders Equity Note [Line Items]
Stock Repurchased During Period, Shares	600,000	7,100,000
Treasury Stock, Value, Acquired, Cost Method					$ 200.0
Stock Repurchased and Retired During Period, Shares			0	0	7,700,000