Income taxes (Details Textual) (USD $)	3 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Taxes [Line Items]
Income Tax Examination, Penalties and Interest Accrued		$ 800,000	$ 700,000
Income Tax Holiday, Aggregate Dollar Amount		100,000	1,100,000	100,000
Undistributed Earnings Of Foreign Subsidiaries		32,400,000
Unrecognized Tax Benefits		2,453,000	2,350,000	2,278,000
Valuation Allowance, Deferred Tax Asset, Change in Amount	7,100,000
Valuation Allowance Deferred Tax Asset From Unrealized Losses On Foreign Currency	700,000
Windfall [Member]
Income Taxes [Line Items]
Operating Loss Carryforwards		4,700,000
Domestic Tax Authority [Member]
Income Taxes [Line Items]
Operating Loss Carryforwards		17,300,000
Foreign Tax Authority [Member]
Income Taxes [Line Items]
Operating Loss Carryforwards		18,900,000
Indian Bureau Of Taxation [Member]
Income Taxes [Line Items]
Tax Adjustments, Settlements, and Unusual Provisions		453,000
Operating Loss Carryforwards Expiration Date 1		These net operating loss carryforwards expire at various times through the year 2033.
Additional Foreign Income Tax Expense Benefit Continuing Operations		1,162,000
Indian Bureau Of Taxation [Member] | Fiscal Tax Year Ended March 31, 2003 [Member]
Income Taxes [Line Items]
Foreign Income Tax Expense (Benefit), Continuing Operations		263,000
Indian Bureau Of Taxation [Member] | Fiscal Tax Year Ended March 31, 2005 [Member]
Income Taxes [Line Items]
Foreign Income Tax Expense (Benefit), Continuing Operations		285,000
Indian Bureau Of Taxation [Member] | Fiscal Tax Year Ended March 31, 2006 [Member]
Income Taxes [Line Items]
Foreign Income Tax Expense (Benefit), Continuing Operations		290,000
Indian Bureau Of Taxation [Member] | Fiscal Tax Year Ended March 31, 2008 [Member]
Income Taxes [Line Items]
Foreign Income Tax Expense (Benefit), Continuing Operations		1,000,000
Philippine Bureau Of Taxation [Member]
Income Taxes [Line Items]
Informal Tax Assessment Received Amount		$ 3,800,000