Components of Company's Debt (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011		Dec. 31, 2010
Debt Instrument [Line Items]
Long term debt	$ 633,389		$ 584,387
2.50% Convertible Notes
Debt Instrument [Line Items]
Long term debt	243,164	[1]
1.875% Convertible Notes
Debt Instrument [Line Items]
Long term debt	278,955	[2]	262,716
Ecko Note
Debt Instrument [Line Items]
Long term debt	67,000		80,000
Asset-Backed Notes
Debt Instrument [Line Items]
Long term debt	44,270		70,650
Term Loan Facility
Debt Instrument [Line Items]
Long term debt			$ 171,021

[1] Reflects the net debt carrying amount of the 2.50% Convertible Notes in the consolidated balance sheet as of December 31, 2011, in accordance with accounting for convertible notes. The principal amount owed to the holders of the Convertible Notes is $300.0 million.

[2] Reflects the net debt carrying amount of the 1.875% Convertible Notes in the consolidated balance sheet as of December 31, 2011, in accordance with accounting for convertible notes. The principal amount owed to the holders of the Convertible Notes is $287.5 million.