CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME [Abstract]
Operating revenues	$ 308,942	$ 288,075	$ 251,145
Operating expenses
Cost of goods and services, exclusive of depreciation and amortization shown separately below	125,140	117,407	106,640
Impairment charge on goodwill	0	10,952	0
Selling, general and administrative, exclusive of depreciation and amortization shown separately below	67,673	60,646	56,445
Depreciation and amortization	60,722	64,412	55,770
Total operating expenses	253,535	253,417	218,855
Operating income (loss)	55,407	34,658	32,290
Other income (expense)
Interest expense	(8,468)	(7,850)	(8,289)
Gain (loss) on investments, net	756	858	(696)
Non-operating income, net	1,769	945	900
Income from continuing operations before income taxes	49,464	28,611	24,205
Income tax expense	19,878	12,008	10,667
Net income from continuing operations	29,586	16,603	13,538
Loss from discontinued operations of Converged Services, net of tax benefits of $0, $196 and $359, respectively	0	(300)	(545)
Net income	29,586	16,303	12,993
Other comprehensive income (loss):
Unrealized gain (loss) on interest rate hedge, net of tax	3,457	(863)	0
Comprehensive income	$ 33,043	$ 15,440	$ 12,993
Basic and diluted net income per share:
Net income from continuing operations (in dollars per share)	$ 1.23	$ 0.69	$ 0.57
Loss from discontinued operations, net of income taxes (in dollars per share)	$ 0	$ (0.01)	$ (0.02)
Net income (in dollars per share)	$ 1.23	$ 0.68	$ 0.55
Weighted average shares outstanding (in shares)	24,001	23,877	23,781
Weighted average shares outstanding, diluted (in shares)	24,115	24,019	23,826