CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Operating revenue:
Equipment	$ 12,910	$ 10,740	$ 28,274	$ 26,039
Services	34,231	33,117	67,636	64,762
Total operating revenue	47,141	43,857	95,910	90,801
Costs and expenses:
Cost of sales, excluding depreciation and amortization	10,860	9,292	24,082	22,758
Cost of services, excluding depreciation and amortization	16,971	15,905	33,570	31,231
Selling, general and administrative expenses	7,047	7,441	14,496	14,147
Asset impairment	5	0	638	0
Depreciation and amortization	7,252	6,732	14,261	12,926
Total costs and expenses	42,135	39,370	87,047	81,062
Operating income	5,006	4,487	8,863	9,739
Other income and expense:
Interest and other income	13	14	15	34
Interest expense	(1,131)	(1,599)	(2,270)	(3,010)
Total other (expense)	(1,118)	(1,585)	(2,255)	(2,976)
Income before income taxes	3,888	2,902	6,608	6,763
Income tax provision	1,567	1,164	2,661	2,731
Net income	$ 2,321	$ 1,738	$ 3,947	$ 4,032
Basic earnings per share	$ 0.17	$ 0.13	$ 0.29	$ 0.30
Weighted average common shares outstanding	13,531,007	13,404,628	13,543,690	13,377,209
Diluted earnings per share	$ 0.17	$ 0.13	$ 0.29	$ 0.30
Weighted average common and equivalent shares outstanding	13,576,967	13,454,707	13,584,749	13,433,277
Dividends per share	$ 0.145	$ 0.14	$ 0.29	$ 0.28