New Accounting Pronouncements (Details) - USD ($) $ in Thousands	Jul. 31, 2019	May 01, 2019	Apr. 30, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets	$ 95,285		$ 0
Operating lease liabilities	$ 96,560
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Operating lease right-of-use assets		$ 80,400
Operating lease liabilities		$ 100,400