Per Share Data (Narrative) (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		3 Months Ended		6 Months Ended
	Jul. 10, 2018	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Income (Loss) from Continuing Operations, Net of Tax, Including Portion Attributable to Noncontrolling Interest		$ 207,000	$ (48,000)	$ 380,000	$ 158,000
Net Income (Loss) Attributable to Noncontrolling Interest		11,000	0	8,000	0
Net Income (Loss) Attributable to Parent		$ 196,000	$ (48,000)	$ 372,000	$ 158,000
Basic weighted average common shares outstanding		4,061	3,998	4,036	3,996
Diluted weighted average common shares outstanding		4,124	3,998	4,095	4,080
Basic net (loss) income per common share		$ 0.05	$ (0.01)	$ 0.09	$ 0.04
Diluted net (loss) income per common share		$ 0.05	$ (0.01)	$ 0.09	$ 0.04
Options and RSUs [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount			113
Options and Restricted Stock Units [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Number of shares that had no effect on computation of dilutive weighted average number of shares outstanding		60	0	55	60
Warrant [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Number of shares that had no effect on computation of dilutive weighted average number of shares outstanding		3	0	4	24
Class of Warrant or Right, Number of Securities Called by Warrants or Rights	55
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 5.25
Proceeds from Warrant Exercises	$ 287,000
Warrant [Member] | SoftBank [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Number of shares that had no effect on computation of dilutive weighted average number of shares outstanding				1	20
Employee Stock Option [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount		6		6	4