Condensed Consolidated Statements of Income (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Income Statement [Abstract]
Revenue	$ 54,045	$ 50,396	$ 165,143	$ 163,133
Operating expense:
Network and facilities expense (excluding depreciation and amortization)	23,016	22,027	71,035	70,716
Operations	7,432	7,182	21,941	22,488
Sales and marketing	1,048	1,090	2,542	4,650
General and administrative	3,645	6,071	12,699	15,105
Depreciation and amortization	2,985	3,293	9,136	11,505
Loss (gain) on disposal of assets	2	3	(29)	226
Loss (gain) on sale of Americas data assets			1,081	(23,171)
Total operating expense	38,128	39,666	118,405	101,519
Income from operations	15,917	10,730	46,738	61,614
Other expense (income):
Interest expense (income)	18	(1)	37	(53)
Other expense (income)		4	(2)	5
Total other expense (income)	18	3	35	(48)
Income from continuing operations before income taxes	15,899	10,727	46,703	61,662
Provision for income taxes	6,123	4,177	18,286	8,524
Income from continuing operations	9,776	6,550	28,417	53,138
Loss from discontinued operations, net of income tax provision		68		7,102
Loss (gain) on disposal of discontinued operations		11		(783)
Net income	$ 9,776	$ 6,471	$ 28,417	$ 46,819
Earnings per share - continuing operations:
Basic	$ 0.30	$ 0.20	$ 0.87	$ 1.64
Diluted	$ 0.29	$ 0.20	$ 0.86	$ 1.63
Loss per share - discontinued operations:
Basic				$ (0.20)
Diluted				$ (0.19)
Earnings per share - net income:
Basic	$ 0.30	$ 0.20	$ 0.87	$ 1.45
Diluted	$ 0.29	$ 0.20	$ 0.86	$ 1.44
Weighted average number of shares outstanding:
Basic	33,115	32,262	32,743	32,344
Diluted	33,343	32,557	33,033	32,548
Dividends paid per share:	$ 0.15	$ 0.06	$ 0.30	$ 1.38