Assets Manufactured for Internal Use (Details 2) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended			9 Months Ended	15 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Sep. 30, 2013	Dec. 31, 2014
Change in estimate of useful life of assets manufactured for internal use
Profit before tax									$ (10,167)	$ (16,104)	$ (32,388)
Net profit	164	(4,704)	(6,900)	174	614	(4,750)	(4,019)	(8,988)	(11,266)	(17,144)	(34,034)
Assets Manufactured for Internal Use | Useful life of assets manufactured for internal use | Adjustment
Change in estimate of useful life of assets manufactured for internal use
Useful life												5 years	10 years
Profit before tax									300	100
Net profit									$ 300	$ 100