Schedule II - Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2015
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	$ 617	$ 888	$ 1,101
Charged to costs and expenses	648	942	1,219
Deductions	(756)	(1,213)	(1,432)
Balance at end of year	509	617	888
Deferred Tax Valuation Allowance [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	77,846	76,420	73,014
Charged to costs and expenses	2,167	1,426	3,406
Deductions	0	0	0
Balance at end of year	$ 80,013	$ 77,846	$ 76,420