Income taxes (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Valuation allowance	$ 2,147		$ 2,147		$ 1,946
Increase (decrease) in valuation allowance from continuing operations	185	163	201	543
Effective income tax rate reconciliation including discontinued operations	(58.90%)	121.50%	(20.90%)	35.50%
Effective income tax rate	(55.00%)	61.30%	(15.70%)	35.50%
Federal statutory rate	35.00%	35.00%	35.00%	35.00%
Management services agreement termination fee paid to Gores	$ 9,000		$ 9,000