Summary of Components of Other Assets (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Goodwill [Line Items]
Fair value of investment	$ 38,741	$ 38,741	$ 26,584	$ 24,584
Operating lease right of use asset (Note 8)	11,673	11,760
Cross currency swap (Note 6)	1,504	3,786
Other intangible assets and other assets	8,483	7,664
Total other assets	139,928	117,655
Shockwave Medical
Goodwill [Line Items]
Investment in Shockwave Medical	$ 79,527	$ 55,704