Summary of Other Equity Investments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2008
Schedule of Equity Method Investments [Line Items]
Other Equity Investments	$ 69,320	$ 68,230
G5
Schedule of Equity Method Investments [Line Items]
Other Equity Investments	19,720	20,595
ABS
Schedule of Equity Method Investments [Line Items]
Other Equity Investments	46,851	45,104
Pan
Schedule of Equity Method Investments [Line Items]
Other Equity Investments	$ 2,749	$ 2,531	$ 4,158