Fair Value of Assets Measured on Recurring and Nonrecurring Basis (Parenthetical) (Detail) (USD $)			12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012	Dec. 31, 2012 Nonrecurring Items
Fair Value Measurements, Recurring and Nonrecurring, Valuation Techniques [Line Items]
Indefinite lived intangible assets, Carrying amount			$ 219,300,000
Indefinite lived intangible assets, Fair value			174,242,000	[1]
Indefinite lived intangible assets, Total loss			45,052,000	[1]
Goodwill	374,434,000	388,385,000	541,400,000
Goodwill, Fair value			213,629,000	[2]
Impairment charges recognized during the period			$ 327,847,000	[2]

[1] In 2012 trademarks and customer relationships with a carrying amount of $219.3 million were written down to their fair value of $174.2 million, resulting in an impairment charge of $45.1 million, which was included in earnings for the period.

[2] In 2012 goodwill with a carrying amount of $ 541.4 million was written down to its fair value of $213.6 million, resulting in an impairment charge of $327.8 million, which was included in earnings for the period.