XML 101 R83.htm IDEA: XBRL DOCUMENT v3.8.0.1
EMPLOYEE BENEFIT PLANS Defined Contribution Plans (Details) - USD ($)
$ in Millions
12 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Mar. 31, 2016
Retirement Benefits [Abstract]      
Defined Contribution Plan, Employer Matching Contribution, Percent of Match 3.00%    
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay 3.00%    
Defined Contribution Plan, Cost $ 22.0 $ 21.8 $ 14.4