SUBSEQUENT EVENTS (Details) - USD ($) $ in Millions		1 Months Ended
	May 09, 2017	Apr. 30, 2017	Apr. 30, 2016	Mar. 31, 2017	Apr. 02, 2015
Senior Notes
Subsequent events
Amount of debt prepaid		$ 100.0	$ 100.0
Aggregate principal amount of notes issued			375.0	$ 475.0	$ 575.0
Payment of a prepayment fee		4.0	$ 5.0
Subsequent events
Subsequent events
Expected one-time charge for reduction in force	$ 5.0
Subsequent events | Senior Notes
Subsequent events
Amount of debt prepaid		100.0
Aggregate principal amount of notes issued		475.0
Payment of a prepayment fee		$ 4.0