Intangible Assets - Intangible Assets, Other than Capitalized Software Development Costs (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Mar. 31, 2019
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	$ 153,150	$ 148,760
Accumulated amortization	(88,756)	(96,165)
Net intangible assets	64,394	52,595
Customer Relationships
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	39,200	54,450
Accumulated amortization	(20,515)	(39,875)
Net intangible assets	18,685	14,575
Trademarks
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	250
Accumulated amortization	(4)
Net intangible assets	246
Computer Software, Intangible Asset
Finite Lived Intangible Assets [Line Items]
Gross carrying amount	113,700	94,310
Accumulated amortization	(68,237)	(56,290)
Net intangible assets	$ 45,463	$ 38,020