CONSOLIDATED STATEMENTS OF STOCKHOLDERS' INVESTMENT AND REDEEMABLE NONCONTROLLING INTERESTS - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Mar. 31, 2016
Increase (Decrease) in Redeemable Noncontrolling Interests [Roll Forward]
Redeemable Noncontrolling Interest - beginning balance	$ 6,886	$ 15,473	$ 26,223
Acquisition of noncontrolling interest	(6,121)		(5,467)
Reclassification from redeemable noncontrolling interest to noncontrolling interests	(835)
Currency translation adjustments	4,163	(1,739)	(1,070)
Net loss	(4,093)	(6,848)	(5,711)
Accretion of noncontrolling interests			1,498
Redeemable Noncontrolling Interest - ending balance	0	6,886	15,473
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders' investment, beginning balance, value	$ 1,289,283	$ 1,504,943	1,613,837
Common stock, shares outstanding - beginning balance	35,213,991	34,976,743
Issuance of common stock	$ 9,808	$ 8,824	18,785
Acquisition of noncontrolling interest	6,121		552
Reclassification from redeemable noncontrolling interest to noncontrolling interests	835
Equity component of 4½% Convertible Senior Notes issued	36,778
Purchase of 4½% Convertible Senior Notes call option	(40,393)
Proceeds from issuance of warrants	30,259
Distributions paid to noncontrolling interests	(49)	(49)	(55)
Dividends paid to noncontrolling interest	(331)	(2,533)	(153)
Common stock dividends	(2,465)	(9,831)	(38,076)
Currency translation adjustments	106	(3,572)	2,479
Net income (loss)	(193,991)	(170,041)	(71,438)
Accretion of redeemable noncontrolling interests	0	0	(1,498)
Other comprehensive loss	42,183	(38,458)	(19,490)
Total stockholders' investment, ending balance, value	$ 1,178,144	$ 1,289,283	$ 1,504,943
Common stock, shares outstanding, ending balance	35,526,625	35,213,991	34,976,743
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders' investment, beginning balance, value	$ 379	$ 377	$ 376
Common stock, shares outstanding - beginning balance	35,213,991	34,976,743	34,838,374
Issuance of common stock	$ 3	$ 2	$ 1
Issuance of common stock, shares	312,634	237,248	138,369
Total stockholders' investment, ending balance, value	$ 382	$ 379	$ 377
Common stock, shares outstanding, ending balance	35,526,625	35,213,991	34,976,743
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders' investment, beginning balance, value	$ 809,995	$ 801,173	$ 781,837
Issuance of common stock	9,805	8,822	18,784
Acquisition of noncontrolling interest	6,121		552
Equity component of 4½% Convertible Senior Notes issued	36,778
Purchase of 4½% Convertible Senior Notes call option	(40,393)
Proceeds from issuance of warrants	30,259
Total stockholders' investment, ending balance, value	852,565	809,995	801,173
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders' investment, beginning balance, value	986,957	1,167,324	1,279,493
Dividends paid to noncontrolling interest			(153)
Common stock dividends	(2,465)	(9,831)	(38,076)
Net income (loss)	(195,658)	(170,536)	(72,442)
Accretion of redeemable noncontrolling interests			(1,498)
Total stockholders' investment, ending balance, value	788,834	986,957	1,167,324
Accumulated Other Comprehensive Loss
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders' investment, beginning balance, value	(328,277)	(289,819)	(270,329)
Other comprehensive loss	42,183	(38,458)	(19,490)
Total stockholders' investment, ending balance, value	(286,094)	(328,277)	(289,819)
Treasury Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders' investment, beginning balance, value	(184,796)	(184,796)	(184,796)
Total stockholders' investment, ending balance, value	(184,796)	(184,796)	(184,796)
Noncontrolling Interests
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Total stockholders' investment, beginning balance, value	5,025	10,684	7,256
Reclassification from redeemable noncontrolling interest to noncontrolling interests	835
Distributions paid to noncontrolling interests	(49)	(49)	(55)
Dividends paid to noncontrolling interest	(331)	(2,533)
Currency translation adjustments	106	(3,572)	2,479
Net income (loss)	1,667	495	1,004
Total stockholders' investment, ending balance, value	$ 7,253	$ 5,025	$ 10,684