Consolidated Balance Sheets - USD ($) $ in Thousands	Jun. 30, 2016	Dec. 31, 2015
Current assets
Cash and cash equivalents	$ 83,914	$ 90,882
Restricted cash (Note 17)	29,600
Accounts receivable, net	54,702	63,498
Inventories, net	70,439	57,619
Other receivables (Note 17)	6,025	31,932
Prepaid expenses	10,241	7,075
Hedge collateral		6,000
Other current assets	2,942	3,228
Total current assets	257,863	260,234
Property, plant and equipment, net	184,665	191,985
Intangible assets, net	2,897	2,629
Long-term prepaid expenses	13,421	12,117
Deferred income tax assets	245	238
Other non-current assets	6,570	6,897
Total assets	465,661	474,100
Current liabilities
Accounts payable	64,243	55,476
Other accounts payable	8,836	10,961
Accrued expenses	80,062	76,721
Deferred revenue	11,310	10,060
Deposits received		8,165
Other current liabilities	4,741	5,128
Total current liabilities	169,192	166,511
Long-term borrowings, net	220,722	220,375
Accrued severance benefits, net	131,841	134,148
Other non-current liabilities	14,235	15,396
Total liabilities	535,990	536,430
Commitments and Contingencies (Note 17)
Stockholders' equity
Common stock, $0.01 par value, 150,000,000 shares authorized, 41,310,519 shares issued and 34,731,754 outstanding at June 30, 2016 and 41,147,707 shares issued and 34,568,942 outstanding at December 31, 2015	412	411
Additional paid-in capital	126,121	124,618
Accumulated deficit	(105,901)	(96,210)
Treasury stock, 6,578,765 shares at June 30, 2016 and December 31, 2015	(90,918)	(90,918)
Accumulated other comprehensive loss	(43)	(231)
Total stockholders' deficit	(70,329)	(62,330)
Total liabilities and stockholders' equity	$ 465,661	$ 474,100