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Income taxes Reconciliation of statutory to effective income tax rate (Details)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Reconciliation of statutory to effective tax rate [Abstract]
Federal Statutory Rate	35.00%	35.00%	35.00%
Permanent differences	54.50%	12.60%	63.20%
State taxes, net of Federal benefit	97.20%	0.10%	6.30%
Foreign earnings taxed at different rates than U.S.	17.40%	(369.50%)	(60.30%)
Valuation allowance	(265.90%)	297.60%	40.80%
Changes in uncertain tax reserves	40.50%	(6.70%)	5.60%
Other	13.40%	0.50%	(26.00%)
Effective tax rate	(7.90%)	(30.40%)	64.60%

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Percentage of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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Percentage of domestic federal statutory tax rate applicable to pretax income (loss).

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