XML 112 R97.htm IDEA: XBRL DOCUMENT v3.8.0.1
Financial Instruments - Percentage of Revenue Generated from Top Customer and Top Five Customers (Detail)
12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Top customer [Member]      
Disclosure of major customers [line items]      
Percentage of revenue generated from customers 6.80% 9.00% 10.90%
Top five customers [Member]      
Disclosure of major customers [line items]      
Percentage of revenue generated from customers 29.40% 32.10% 30.70%