CONDENSED CONSOLIDATED STATEMENT OF EQUITY - 3 months ended Jun. 30, 2018 - USD ($) $ in Thousands	Total	Common Stock	Additional paid-in Capital	Retained earnings	Accumulated other comprehensive income (loss)	Treasury Stock
Balance, beginning of the period (in shares) at Mar. 31, 2018		136,079,676				(58,304,917)
Balance, beginning of the period at Mar. 31, 2018	$ 749,095	$ 13,609	$ 1,235,679	$ 628,331	$ 10,767	$ (1,139,291)
Increase (Decrease) in Stockholders' Equity
Employee stock awards, benefit plans and other issuances (in shares)		233,784				(391,898)
Employee stock awards, benefit plans and other issuances	(5,928)	$ 23	4,093	0		$ (10,044)
Non-cash stock-based compensation (in shares)		149,416
Non-cash stock-based compensation	16,811	$ 15	16,796
Restricted stock units vested (in shares)		1,259,681
Restricted stock units vested	0	$ 126	(126)
Acquisition of treasury stock (in shares)						(1,853,071)
Acquisition of treasury stock	(45,766)					$ (45,766)
Other comprehensive income (loss):
Foreign currency translation	(1,868)				(1,868)
Net loss	(3,015)			(3,015)
Balance, end of the period (in shares) at Jun. 30, 2018		137,722,557				(60,549,886)
Balance, end of the period at Jun. 30, 2018	$ 722,056	$ 13,773	$ 1,256,442	$ 638,043	$ 8,899	$ (1,195,101)