Investments - Components of Company's Investments (Detail) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	$ 13,182	$ 11,902
U.S. non-qualified deferred compensation plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	12,729	11,401
Warrants and equity securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	$ 453	$ 501