Income taxes (Details 1) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Income Tax Disclosure [Abstract]
Computed tax benefit at the federal statutory rate of 35%	$ 591	$ 19,069	$ 4,879
State income taxes, net of federal benefit	(19)	(57)	(50)
Non-deductible compensation	(91)	(537)	(30)
Non-deductible expense	(113)	(131)	(132)
Non-deductible goodwill impairment	1,257	(15,490)	0
Tax on foreign income	(104)	(252)	(262)
Valuation allowance	(1,686)	(4,186)	(6,090)
Other	81	(18)	105
Income tax provision	$ (84)	$ (1,602)	$ (1,580)
Effective tax rate	5.00%	2.90%	11.30%