Earnings per share (Details) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Earnings Per Share [Abstract]
Net loss	$ (9,507)		$ (12,023)		$ (30,638)		$ (28,701)
Amount allocated to common shareholders (in hundredths)	100.00%	[1]	100.00%	[1]	100.00%		100.00%
Basic EPS:
Net loss allocated to common shareholders	(9,507)		(12,023)		(30,638)		(28,701)
Net loss allocable to common shareholders - (in Shares)	88,611,000		88,468,000		88,588,000		88,549,000
Earnings Per Share, Basic	$ (0.11)		$ (0.14)		$ (0.35)		$ (0.32)
Diluted EPS:
Net loss applicable to common shareholders with assumed conversion	$ (9,507)		$ (12,023)		$ (30,638)		$ (28,701)
Net loss applicable to common shareholders with assumed conversion - (in Shares)	88,611,000		88,468,000		88,588,000		88,549,000
Earnings Per Share, Diluted	$ (0.11)		$ (0.14)		$ (0.35)		$ (0.32)
Stock Options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted EPS (in shares)	620,334	[2]	626,334	[2]	620,334	[2]	626,334	[2]
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from calculation of diluted EPS (in shares)	573,628	[2]	406,070	[2]	522,032	[2]	382,462	[2]

[1] We have not allocated net losses between common and preferred shareholders, as the holders of our preferred shares do not have a contractual obligation to share in the loss.

[2] In periods when we report a net loss, all share awards are excluded from the calculation of diluted weighted average stock outstanding because of their antidilutive effect on earnings (loss) per share.