Debt - Additional Information (Detail) (USD $)	12 Months Ended								12 Months Ended		12 Months Ended			12 Months Ended							1 Months Ended	12 Months Ended		12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2012 Credit Agreement	Dec. 31, 2011 Credit Agreement	Dec. 31, 2012 Foreign Facilities	Dec. 31, 2012 Combined Facilities	Dec. 31, 2011 Combined Facilities	Dec. 31, 2012 Senior Notes Eight Point Twenty Five Percent Due March Fifteen Two Thousand Nineteen	Mar. 13, 2012 Senior Notes Eight Point Twenty Five Percent Due March Fifteen Two Thousand Nineteen	Dec. 31, 2012 Senior Notes Four Point Nine Five Percent Due April One Two Thousand Fourteen	Dec. 31, 2012 Senior Notes Five Point Five Zero Percent Due May Fifteen Two Thousand Fifteen	Dec. 31, 2011 Senior Notes Five Point Five Zero Percent Due May Fifteen Two Thousand Fifteen	Dec. 31, 2012 Senior Notes Five Point Six Two Five Percent Due January Fifteen Two Thousand Twelve	Dec. 31, 2012 Revolving Credit Facility	Dec. 31, 2012 Revolving Credit Facility New Credit Agreement	Dec. 31, 2012 Revolving Credit Facility Prior Credit Agreement	Dec. 31, 2012 Senior Notes Seven Point Twenty Five Percent Due May Fifteen Two Thousand Eighteen	Dec. 31, 2011 Senior Notes Seven Point Twenty Five Percent Due May Fifteen Two Thousand Eighteen	Jun. 01, 2011 Senior Notes Seven Point Twenty Five Percent Due May Fifteen Two Thousand Eighteen	Sep. 28, 2011 Senior Notes Eleven Point Two Five Percent Due February One Two Thousand Nineteen	Dec. 31, 2012 Senior Notes Eleven Point Two Five Percent Due February One Two Thousand Nineteen	Dec. 31, 2011 Senior Notes Eleven Point Two Five Percent Due February One Two Thousand Nineteen	Dec. 31, 2012 Senior Notes Six Point One Two Five Percent Due January Fifteen Two Thousand Seventeen	Dec. 31, 2011 Senior Notes Six Point One Two Five Percent Due January Fifteen Two Thousand Seventeen
Debt Disclosure [Line Items]
Amount of difference between fair value and book value	$ 3,700,000	$ 80,100,000
Credit facility, maximum borrowing capacity						170,000,000										1,150,000,000	1,750,000,000
Revolving credit agreement expiration date																Oct. 15, 2017	Dec. 17, 2013
Pre-tax loss on debt extinguishment	23,200,000														4,000,000
Allowable annual dividend payment under credit agreement				200,000,000
Debt instrument, face amount									450,000,000	450,000,000										600,000,000
Interest rate									8.25%	8.25%	4.95%	5.50%	5.50%	5.625%					7.25%		11.25%		11.25%		6.125%
Repurchase of debt											341,800,000	100,000,000		158,600,000							11,600,000	216,200,000		100,000,000
Pre-tax loss on debt extinguishment	12,100,000	69,900,000
Gain due to termination of the related interest rate swaps	11,100,000
Maturity date									Mar. 15, 2019		Apr. 01, 2014	May 15, 2015						May 15, 2018			Feb. 01, 2019	Feb. 01, 2019		Jan. 15, 2017
Credit facility borrowings				0	65,000,000		10,400,000	82,200,000
Weighted average interest rate on borrowings, per annum				2.19%	2.08%
Outstanding letters of credit	71,100,000
Credit facility, remaining borrowing capacity							1,300,000,000
Interest paid	$ 250,100,000	$ 252,200,000	$ 235,200,000