Computation of loss per share - Computation of Loss per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Numerator:
Net loss from continuing operations	$ (2,894)	$ 1,398	$ (709)	$ (821)	$ (172)	$ 737	$ 28	$ (812)	$ (3,026)	$ (219)	$ (1,318)
Net loss from discontinued operations	1,672	(74,092)	(16,264)	68,493	(15,724)	(10,837)	(4,191)	(5,004)	(20,191)	(35,756)	(12,695)
Net loss	$ (1,222)	$ (72,694)	$ (16,973)	$ 67,672	$ (15,896)	$ (10,100)	$ (4,163)	$ (5,816)	$ (23,217)	$ (35,975)	$ (14,013)
Denominator:
Basic and dilutive weighted average shares outstanding									16,426,455	16,391,252	16,326,760
Basic and diluted loss per share from continuing operations	$ (0.18)	$ 0.09	$ (0.04)	$ (0.05)	$ (0.01)	$ 0.04	$ 0.00	$ (0.05)	$ (0.18)	$ (0.01)	$ (0.08)
Basic and diluted loss per share from discontinued operations									$ (1.23)	$ (2.18)	$ (0.78)
Basic and diluted loss per share									$ (1.41)	$ (2.19)	$ (0.86)