SHARE REPURCHASE PLAN (Details) shares in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016 USD ($) shares	Mar. 31, 2017 USD ($) plan shares
Repurchase plan information
Aggregate shares repurchased (in shares) | shares		25.1
Aggregate purchase value of shares repurchased		$ 345,800,000
Number of share repurchase plans | plan		2
Authorized amount of stock repurchase program		$ 500,000,000
Stock repurchased during period (shares) | shares		14.7
Stock repurchased during period		$ 214,700,000
Remaining authorized repurchase amount		$ 285,300,000
Share repurchase plan authorized at 2013 extraordinary general meeting
Repurchase plan information
Aggregate shares repurchased (in shares) | shares	10.4
Aggregate purchase value of shares repurchased	$ 131,100,000