Investments - Components of Company's Investments (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	$ 15,281	$ 13,989
U.S. Non-Qualified Deferred Compensation Plan [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	15,028	13,709
Warrants and Equity Securities [Member]
Schedule of Fair Value of Separate Accounts by Major Category of Investment [Line Items]
Total	$ 253	$ 280