EARNINGS PER SHARE ("EPS") (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jun. 30, 2018	Jun. 30, 2017
Computation of Basic earnings per share:
Net income	$ 71,693	$ 60,276	[1]
Less: net income allocated to participating securities	0	(588)
Net income for basic earnings per share calculation	$ 71,693	$ 59,688
Total weighted average shares outstanding—basic (in shares)	112,941	105,494
Less: weighted average participating shares outstanding (in shares)	0	(1,029)
Weighted average common shares outstanding—basic (in shares)	112,941	104,465
Basic earnings (loss) per share (in dollars per share)	$ 0.63	$ 0.57
Earnings Per Share, Diluted [Abstract]
Net income	$ 71,693	$ 60,276	[1]
Less: net income allocated to participating securities	0	(522)
Add: interest expense, net of tax, on Convertible Notes	95	5,750
Net income (loss) for diluted earnings (loss) per share calculation	$ 71,788	$ 65,504
Weighted average common shares outstanding—basic (in shares)	112,941	105,494
Add: dilutive effect of common stock equivalents (in shares)	3,044	13,288
Weighted average common shares outstanding—diluted (in shares)	115,985	118,782
Less: weighted average participating shares outstanding (in shares)	0	(1,029)
Weighted average common shares outstanding- diluted (in shares)	115,985	117,753
Diluted earnings (loss) per share (in dollars per share)	$ 0.62	$ 0.56

[1] Prior period amounts have been adjusted retrospectively to reflect the adoption of ASU 2016-08, Statement of Cash Flows (Topic 230): Restricted Cash. Refer to Note 1 for further discussion.