Equity - Accumulated other comprehensive income (Details) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2014
Components of Accumulated Other Comprehensive Loss
Beginning Balance	$ (2,854)
Currency translation adjustment, net of income tax expense of $2,342	3,716
Changes related to benefit plans, net of income tax benefit	(3)
Ending Balance	859
Currency Translation [Member]
Components of Accumulated Other Comprehensive Loss
Beginning Balance	(4,508)
Currency translation adjustment, net of income tax expense of $2,342	3,716
Changes related to benefit plans, net of income tax benefit	0
Ending Balance	(792)
Employee Benefit Plans [Member]
Components of Accumulated Other Comprehensive Loss
Beginning Balance	1,654
Currency translation adjustment, net of income tax expense of $2,342	0
Changes related to benefit plans, net of income tax benefit	(3)
Ending Balance	$ 1,651