Schedule of Other Long-Term Investments (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Investment [Line Items]
Other long-term investments	$ 18,539	$ 26,167
Mortgage Loans, At Cost
Investment [Line Items]
Other long-term investments	514	551
Investment Real Estate, At Depreciated Cost
Investment [Line Items]
Other long-term investments	2,816	3,165
Low-Income Housing Interests
Investment [Line Items]
Other long-term investments	9,875	12,188
Collateral Loans
Investment [Line Items]
Other long-term investments	0	7,598
Other
Investment [Line Items]
Other long-term investments	$ 5,334	$ 2,665