New Accounting Pronouncements - Cumulative Effects of Accounting Standards Update on Statement of Comprehensive Income and Balance Sheet (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions	3 Months Ended		9 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2019	Dec. 31, 2018
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Service revenue	$ 8,080,000	$ 8,601,000	$ 24,017,000	$ 25,159,000
Revenue, equipment sales, net	1,372,000	1,589,000	3,784,000	4,180,000
Revenue, equipment rentals, net	1,292,000	1,313,000	3,981,000	3,778,000
Revenues	8,080,000	8,601,000	24,017,000	25,159,000
Cost of equipment sales	1,646,000	1,734,000	4,346,000	4,521,000
Cost of equipment rentals	201,000	182,000	666,000	457,000
Selling, general and administrative	2,045,000	2,003,000	5,888,000	5,731,000
Severance and exit costs	20,000		66,000
Depreciation, network and other	1,071,000	1,088,000	3,256,000	3,132,000
Depreciation, equipment rentals	1,011,000	1,137,000	3,096,000	3,454,000
Amortization	474,000	145,000	698,000	475,000
Other, net	(152,000)	185,000	106,000	298,000
Total costs and expenses	8,014,000	8,122,000	23,259,000	23,087,000
Operating Income	66,000	479,000	758,000	2,072,000
Total other expense	(595,000)	(632,000)	(1,766,000)	(1,781,000)
Loss (income) before income taxes	(529,000)	(153,000)	(1,008,000)	291,000
Income tax benefit	408,000	8,000	494,000	(56,000)
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest	(121,000)	(145,000)	(514,000)	235,000
Net Income (Loss) Attributable to Noncontrolling Interest	1,000	4,000	9,000	(4,000)
Net Income (Loss) Attributable to Parent	$ (120,000)	$ (141,000)	$ (505,000)	$ 231,000
Basic net (loss) income per common share	$ (0.03)	$ (0.03)	$ (0.12)	$ 0.06
Diluted net (loss) income per common share	$ (0.03)	$ (0.03)	$ (0.12)	$ 0.06
Basic weighted average common shares outstanding	4,109	4,078	4,098	4,050
Diluted weighted average common shares outstanding	4,109	4,078	4,098	4,110
Services [Member]
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Service revenue	$ 5,416,000	$ 5,699,000	$ 16,252,000	$ 17,201,000