CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Operating revenue:
Equipment	$ 12,849	$ 12,915	$ 41,123	$ 38,954
Services	34,239	32,898	101,875	97,660
Total operating revenue	47,088	45,813	142,998	136,614
Costs and expenses:
Cost of sales, excluding depreciation and amortization	10,929	10,906	35,011	33,664
Cost of services, excluding depreciation and amortization	17,406	16,358	50,976	47,589
Selling, general and administrative expenses	6,953	7,123	21,449	21,270
Asset impairment	0	0	638	0
Depreciation and amortization	7,514	6,869	21,775	19,795
Total costs and expenses	42,802	41,256	129,849	122,318
Operating income	4,286	4,557	13,149	14,296
Other income and expense:
Interest and other income	1	3	16	37
Interest expense	(1,155)	(1,625)	(3,425)	(4,635)
Total other expense	(1,154)	(1,622)	(3,409)	(4,598)
Income before income taxes	3,132	2,935	9,740	9,698
Income tax provision	1,270	1,194	3,931	3,925
Net income	$ 1,862	$ 1,741	$ 5,809	$ 5,773
Basic earnings per share	$ 0.14	$ 0.13	$ 0.43	$ 0.43
Weighted average common shares outstanding	13,543,062	13,427,883	13,543,479	13,394,224
Diluted earnings per share	$ 0.14	$ 0.13	$ 0.43	$ 0.43
Weighted average common and equivalent shares outstanding	13,592,577	13,485,143	13,594,198	13,452,642
Dividends per share	$ 0.145	$ 0.14	$ 0.435	$ 0.42