Taxation (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Tax Benefit from Stock Options Exercised	$ 7	$ 67	$ 0
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	4,631	4,922
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued	0	0	3
Unrecognized Tax Benefits, Income Tax Penalties and Interest Expense	117	65	42
Deferred Tax Assets, Operating Loss Carryforwards, Foreign	7,294
Deferred Tax Assets, Valuation Allowance	2,006	1,833	1,868	1,327
Fully Vested Options Expired Unexercised
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	379	121
Restricted Stock
Deferred Tax Assets, Tax Deferred Expense, Compensation and Benefits, Share-based Compensation Cost	$ 58	$ 3,255