Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018		Dec. 31, 2017
Statement of Cash Flows [Abstract]
Restricted Cash		$ 3,134	$ 0	$ 3,134		$ 0
Net income (loss)	[1],[2]	40,806	18,589	113,167		251,847
Operating Activities:
Depreciation and amortization (1)		12,763	11,353	38,405	[3]	37,366	[3]
Equity (income) loss from equity method investments		296	(238)	301		(75,879)
Acquisition (gain) loss		0	(310)	0		(137,183)
Non-cash debt and financing costs				1,085		1,820
(Gain) loss on early extinguishment of debt				15,988		486
Stock-based compensation expense				10,011		4,837
Provision for Doubtful Accounts				84		162
(Gain) loss on write down and disposal of long-lived assets		788	(902)	1,611		(922)
Pension and other post-retirement benefits				3,823		3,897
Change in deferred income taxes (1)	[3]			1,395		(3,792)
Change in operating assets (1)	[3]			(42,130)		25,820
Change in operating liabilities (1)	[3]			(61,485)		(26,258)
Other (1)				472		582
Net cash provided by (used in) operating activities (1)	[3]			82,727		82,783
Investing activities:
Capital expenditures				(77,650)		(30,925)
Acquisitions, net of cash received				0		167,129
Proceeds from Sale of Productive Assets				169		1,227
Payments to Acquire Interest in Joint Venture				(2,000)		0
Net cash provided by (used in) investing activities				(78,705)		140,162
Financing activities:
Payments of revolving line of credit				0		(33,881)
Proceeds from Issuance of Secured Debt				293,348		334,978
Payment for Debt Extinguishment or Debt Prepayment Cost				(3,234)		0
Payments of Debt Issuance Costs				(1,797)		(5,002)
Payments of long-term debt				(332,063)		(361,625)
Proceeds from exercise of stock options				480		5,122
Payments of Ordinary Dividends, Common Stock				(2,873)		0
Proceeds from Equity Method Investment, Distribution				776		2,731
Proceeds from Warrant Exercises				0		8,838
Net cash provided by (used in) financing activities				(46,139)		(51,570)
Net increase (decrease) in cash, cash equivalents and restricted cash				(42,117)		171,375
Effect of foreign currency fluctuations on cash, cash equivalents and restricted cash (1)	[3]			(7,236)		3,017
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents		237,493	284,166	237,493		284,166
Cash, cash equivalents, and restricted cash, at end of fiscal period		$ 234,359	$ 284,166	$ 234,359		$ 284,166

[1] Three and nine months ended December 31, 2017 adjusted due to the adoption of ASC 606.

[2] Three and nine months ended December 31, 2017 adjusted due to the adoption of ASC 606.

[3] Nine months ended December 31, 2017 adjusted due to the adoption of ASC 606.