Operations by Business Segment (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Apr. 04, 2015		Mar. 29, 2014		Dec. 31, 2014
Segment Reporting Information [Line Items]
Number of reportable segments	2
Revenues	$ 174,292		$ 157,387
Income (loss) from operations	(3,985)		(4,725)
Interest expense	(790)		(719)
Interest income	63		69
Other income (expense), net	(827)		(805)
Income before income taxes	(5,539)		(6,180)
Segment assets, total	380,849		341,206		381,004
Utility services [Member]
Segment Reporting Information [Line Items]
Revenues	100,383		89,292
Income (loss) from operations	3,885		2,785
Segment assets, total	148,924		140,643
Residential commercial services [Member]
Segment Reporting Information [Line Items]
Revenues	73,457		67,807
Income (loss) from operations	(3,889)		(4,237)
Segment assets, total	144,532		130,437
All other [Member]
Segment Reporting Information [Line Items]
Revenues	452		288
Income (loss) from operations	(2,615)		(2,516)
Segment assets, total	0		0
Reconciling adjustments [Member]
Segment Reporting Information [Line Items]
Revenues	0		0
Income (loss) from operations	(1,366)	[1]	(757)	[1]
Interest expense	(790)		(719)
Interest income	63		69
Other income (expense), net	(827)		(805)
Segment assets, total	$ 87,393	[2]	$ 70,126	[2]

[1] (a)Reclassification of depreciation expense and allocation of corporate expenses.

[2] (b)Corporate assets include cash, prepaid expenses, corporate facilities, enterprise-wide information systems and other nonoperating assets.