Operations by Business Segment and Geographic Information Operations by business segment (Tables)

12 Months Ended

Dec. 31, 2016

Segment Reporting [Abstract]

Schedule of segment reporting information, by segment [Table Text Block]

Information on reportable segments and reconciliation to the consolidated financial statements follows: 

	Utility Services		Residential Commercial Services		All Other			Reconciling  Adjustments				Consolidated
Fiscal Year 2016
Revenues	$	433,379	$	410,878	$	1,421		$	—			$	845,678
Income (loss) from operations	19,256		36,640		(4,318		)	(6,207		)	(a)	45,371
Interest expense								(4,393		)		(4,393		)
Interest income								255				255
Other income (expense), net								(3,989		)		(3,989		)
Income before income taxes												$	37,244
Depreciation	$	26,855	$	17,198	$	—		$	3,231		(b)	$	47,284
Amortization	135		2,136		—			35				2,306
Capital expenditures	28,660		21,819		—			6,167				56,646
Segment assets, total	171,220		166,858		—			85,861			(c)	423,939
Fiscal Year 2015
Revenues	$	433,117	$	386,327	$	2,460		$	—			$	821,904
Income (loss) from operations	24,273		35,271		(5,368		)	(10,068		)	(a)	44,108
Interest expense								(3,355		)		(3,355		)
Interest income								249				249
Other income (expense), net								(5,744		)		(5,744		)
Income before income taxes												$	35,258
Depreciation	$	25,466	$	15,592	$	—		$	3,619		(b)	$	44,677
Amortization	144		2,062		—			8				2,214
Capital expenditures	26,853		22,853		—			6,341				56,047
Segment assets, total	145,306		162,679		—			85,601			(c)	393,586
Fiscal Year 2014
Revenues	$	404,519	$	386,274	$	(882	)	$	—			$	789,911
Income (loss) from operations	21,382		37,232		(6,037		)	(8,574		)	(a)	44,003
Interest expense								(2,948		)		(2,948		)
Interest income								295				295
Other income (expense), net								(3,050		)		(3,050		)
Income before income taxes												$	38,300
Depreciation	$	23,225	$	14,544	$	—		$	3,201		(b)	$	40,970
Amortization	174		1,896		—			—				2,070
Capital expenditures	25,994		17,490		—			12,247				55,731
Segment assets, total	150,002		144,413		—			86,589			(c)	381,004

Schedule of revenue from external customers attributed to foreign countries by geographic area [Table Text Block]

Geographic Information--The following presents revenues and long-lived assets by geographic territory:

	Year Ended December 31,
	2016		2015		2014
Revenues
United States	$	775,870	$	749,896	$	706,145
Canada	69,808		72,008		83,766
	$	845,678	$	821,904	$	789,911
	December 31,
	2016		2015		2014
Long-lived assets, net
United States	$	224,727	$	213,323	$	196,116
Canada	20,439		19,329		17,692
	$	245,166	$	232,652	$	213,808