Note 10 - Change in Accounting Principle (Tables)

9 Months Ended

Sep. 30, 2015

Cash Flow [Member]

Notes Tables

Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]

	September 30, 2014
	Prior to Change in Accounting Principle			Effect of Change			Recast
Cash Flow:
Net income	$	1,850		$	883		$	2,733
Depreciation and amortization		33,274			121			33,395
Deferred income taxes		(4,176	)		551			(3,625	)
Inventories, prepaid expenses and other current assets		(458	)		(1,555	)		(2,013	)

Statement of Operations [Member]

Notes Tables

Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]

	Three Months Ended September 30, 2014							Nine Months Ended September 30, 2014
	Prior to Change in Accounting Principle		Effect of Change			Recast		Prior to Change in Accounting Principle		Effect of Change			Recast
Statement of Operations:
Operations and maintenance	$	12,863	$	(2,214	)	$	10,649	$	37,554	$	(1,555	)	$	35,999
Depreciation and amortization		10,671		121			10,792		33,274		121			33,395
Operating income		5,419		2,093			7,512		8,633		1,434			10,067
Income before income taxes		4,534		2,093			6,627		3,717		1,434			5,151
Income tax expense		1,817		804			2,621		1,867		551			2,418
Net income and Comprehensive income		2,717		1,289			4,006		1,850		883			2,733
Average shares outstanding (basic)		10,357		--			--		10,350		--			--
Basic earnings per share		0.26		0.13			0.39		0.18		0.09			0.26
Average shares outstanding (diluted)		10,476		--			--		10,482		--			--
Diluted earnings per share		0.26		0.12			0.38		0.18		0.08			0.26

	Three Months Ended March 31, 2015							Three Months Ended June 30, 2015							Six Months Ended June 30, 2015
	Prior to Change in Accounting Principle		Effect of Change			Recast		Prior to Change in Accounting Principle		Effect of Change			Recast		Prior to Change in Accounting Principle		Effect of Change			Recast
Operations and maintenance	$	12,140	$	(1,066	)	$	11,074	$	12,176	$	(700	)	$	11,476	$	24,316	$	(1,766	)	$	22,550
Depreciation and amortization		10,671		131			10,802		10,277		170			10,447		20,948		301			21,249
Operating income		3,591		935			4,526		5,284		530			5,814		8,875		1,465			10,340
Income before income taxes		2,009		935			2,944		4,365		530			4,895		6,374		1,465			7,839
Income tax expense		893		416			1,309		1,905		220			2,125		2,798		636			3,434
Net income and Comprehensive income		1,116		519			1,635		2,460		310			2,770		3,576		829			4,405
Average shares outstanding (basic)		10,395		--			--		10,435		--			--		10,423		--			--
Basic earnings per share		0.11		0.05			0.16		0.24		0.03			0.27		0.34		0.08			0.42
Average shares outstanding (diluted)		10,516		--			--		10,516		--			--		10,524		--			--
Diluted earnings per share		0.11		0.05			0.16		0.23		0.03			0.26		0.34		0.08			0.42

	Three Months Ended March 31, 2014									Three Months Ended June 30, 2014							Six Months Ended June 30, 2014
	Prior to Change in Accounting Principle			Effect of Change			Recast			Prior to Change in Accounting Principle		Effect of Change			Recast		Prior to Change in Accounting Principle			Effect of Change			Recast
Operations and maintenance	$	13,062		$	9		$	13,071		$	11,629	$	650		$	12,279	$	24,691		$	659		$	25,350
Operating income (loss)		(1,043	)		(9	)		(1,052	)		4,257		(650	)		3,607		3,214			(659	)		2,555
Income (loss) before income taxes		(2,183	)		(9	)		(2,192	)		1,366		(650	)		716		(817	)		(659	)		(1,476	)
Income tax expense (benefit)		(594	)		(3	)		(597	)		644		(250	)		394		50			(253	)		(203	)
Net income (loss) and Comprehensive income (loss)		(1,589	)		(6	)		(1,595	)		722		(400	)		322		(867	)		(406	)		(1,273	)
Average shares outstanding (basic)		10,339			--			--			10,346		--			--		10,343			--			--
Basic earnings (loss) per share		(0.15	)		0.00			(0.15	)		0.07		(0.04	)		0.03		(0.08	)		(0.04	)		(0.12	)
Average shares outstanding (diluted)		10,399			--			--			10,478		--			--		10,343			--			--
Diluted earnings (loss) per share		(0.15	)		0.00			(0.15	)		0.07		(0.04	)		0.03		(0.08	)		(0.04	)		(0.12	)

Balance Sheet [Member]

Notes Tables

Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]

	December 31, 2014
	Prior to Change in Accounting Principle			Effect of Change			Recast
Balance Sheet:
Prepaid expenses and other current assets	$	17,318		$	(12,121	)	$	5,197
Deferred income taxes		46,688			(3,917	)		42,771
Property and equipment		16,648			2,164			18,812
Accumulated depreciation and amortization		(182,724	)		(240	)		(182,964	)
Retained earnings		61,082			(6,280	)		54,802