Disposition of Assets (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
Proceeds from sale of subsidiary			$ 0	$ 1,108
Loss on sale of subsidiary			0	608
Loss from discontinued operation, net of income taxes	$ (114)	$ (1,435)	$ (469)	$ (3,476)
From discontinued operation (in US dollars per share)	$ 0.00	$ (0.02)	$ (0.01)	$ (0.05)
Restructuring reserve	$ 541	$ 155	$ 541	$ 155	$ 281	$ 194
UNITED STATES | United States Building Services [Member] | United States Building Services Subsidiary [Member]
Income Statement [Abstract]
Proceeds from sale of subsidiary				1,100
UNITED STATES | Selling, General and Administrative Expenses [Member] | United States Building Services [Member] | United States Building Services Subsidiary [Member]
Income Statement [Abstract]
Loss on sale of subsidiary				600
UNITED KINGDOM | Discontinued Operations [Member] | United Kingdom Construction [Member]
Income Statement [Abstract]
Revenues	84	5,137	360	13,983
Loss from discontinued operation, net of income taxes	$ (114)	$ (1,435)	$ (469)	$ (3,476)
From discontinued operation (in US dollars per share)	$ 0.00	$ (0.02)	$ (0.01)	$ (0.05)
Assets of discontinued operation:
Current assets	$ 4,318		$ 4,318		6,265
Non-current assets	114		114		278
Liabilities of discontinued operation:
Current liabilities	8,007		8,007		10,743
Non-current liabilities	35		35		$ 94
SeveranceandFacilityClosing [Member] | UNITED KINGDOM | Discontinued Operations [Member] | United Kingdom Construction [Member]
Income Statement [Abstract]
Restructuring reserve	$ 1,100		$ 1,100