Condensed Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2019	Mar. 31, 2019
Current assets:
Cash and cash equivalents	$ 192,702
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents	193,258	$ 207,918
Accounts receivable, net	163,398	154,059
Inventories, net	268,220	241,129
Prepaid expenses and other current assets	48,571	38,947
Total current assets	672,891	642,053
Noncurrent Assets:
Property, plant and equipment, net of accumulated depreciation of $891,155 and $880,451 as of September 30, 2019 and March 31, 2019, respectively	527,887	495,280
Goodwill	40,294	40,294
Intangible assets, net	56,358	53,749
Equity method investments	13,673	12,925
Equity method investments	45,027	57,024
Other assets	45,595	16,770
Total assets	1,401,725	1,318,095
Current liabilities:
Current portion of long-term debt	29,164	28,430
Accounts payable	137,263	153,287
Accrued expenses	143,977	93,761
Income taxes payable	2,265	2,995
Total current liabilities	312,669	278,473
Liabilities, Noncurrent [Abstract]
Long-term debt	276,429	266,041
Other non-current obligations	148,835	125,360
Deferred Tax Liabilities, Net, Noncurrent	12,875	8,806
Liabilities	750,808	678,680
Stockholders’ equity:
Preferred stock, par value $0.01, authorized 10,000 shares, none issued	0	0
Common stock, par value $0.01, authorized 175,000 shares, issued 58,067 and 57,822 shares at September 30, 2019 and March 31, 2019, respectively	581	578
Additional paid-in capital	470,937	465,366
Retained earnings (deficit)	223,472	204,195
Accumulated other comprehensive income (loss)	(44,073)	(30,724)
Total stockholders’ equity	650,917	639,415
Total liabilities and stockholders’ equity	$ 1,401,725	$ 1,318,095