Revenue - Schedule of Contract Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Mar. 31, 2019
Contract assets:
Current	$ 928,056	$ 846,372
Long-term	61,892	61,391
Total	989,948	907,763
Contract liabilities:
Advance payments, billings in excess of costs incurred and deferred revenue	$ 30,585	$ 21,316