CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Current assets
Cash and cash equivalents	$ 542,111	$ 151,657
Accounts receivable, net	57,772	47,447
Inventories, net	33,631	41,404
Other receivables	4,551	10,200
Prepaid expenses	8,265	9,003
Hedge collateral (Note 9)	9,650	9,820
Other current assets (Notes 10 and 18)	8,338	10,013
Current assets held for sale (Note 2)		99,821
Total current assets	664,318	379,365
Property, plant and equipment, net	77,489	73,068
Operating lease right-of-use assets	2,032	1,876
Intangible assets, net	2,877	2,769
Long-term prepaid expenses	2,138	5,757
Other non-current assets	8,598	9,059
Non-current assets held for sale (Note 2)		123,434
Total assets	757,452	595,328
Current liabilities
Accounts payable	40,497	40,376
Other accounts payable	7,639	6,410
Accrued expenses (Note 8)	41,630	44,799
Accrued income taxes	14,038	1,569
Operating lease liabilities	1,390	1,625
Current portion of long-term borrowings, net	306,567
Other current liabilities (Note 10)	7,652	2,014
Current liabilities held for sale (Note 2)		37,040
Total current liabilities	419,413	133,833
Long-term borrowings, net	0	304,743
Accrued severance benefits, net	51,953	51,181
Other non-current liabilities	7,782	9,671
Non-current liabilities held for sale (Note 2)		110,881
Total liabilities	479,148	610,309
Commitments and contingencies (Note 18)
Stockholders' equity
Common stock, $0.01 par value, 150,000,000 shares authorized, 44,595,393 shares issued and 35,489,720 outstanding at September 30, 2020 and 43,851,991 shares issued and 34,800,312 outstanding at December 31, 2019	447	439
Additional paid-in capital	159,840	152,404
Retained earnings (deficit)	220,253	(58,131)
Treasury stock, 9,105,673 shares at September 30, 2020 and 9,051,679 shares at December 31, 2019, respectively	(107,649)	(107,033)
Accumulated other comprehensive income (loss)	5,413	(2,660)
Total stockholders' equity (deficit)	278,304	(14,981)
Total liabilities and stockholders' equity	$ 757,452	$ 595,328