CONSOLIDATED BALANCE SHEETS (USD $) In Thousands, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011
Current assets
Cash and cash equivalents	$ 165,658	$ 162,111
Restricted cash	136	6,830
Accounts receivable, net	148,537	125,922
Inventories, net	75,020	62,836
Other receivables	2,097	256
Prepaid expenses	9,120	6,032
Other current assets	19,270	15,909
Total current assets	419,838	379,896
Property, plant and equipment, net	229,632	182,663
Intangible assets, net	16,684	16,787
Long-term prepaid expenses	9,575	4,790
Other non-current assets	17,044	18,539
Total assets	692,773	602,675
Current liabilities
Accounts payable	97,386	77,848
Other accounts payable	19,049	13,452
Accrued expenses	40,483	31,723
Current portion of capital lease obligations		2,852
Derivative liabilities	1,818	9,757
Other current liabilities	8,460	2,007
Total current liabilities	167,196	137,639
Long-term borrowings, net	201,586	201,389
Accrued severance benefits, net	105,051	90,755
Other non-current liabilities	11,556	6,222
Total liabilities	485,389	436,005
Stockholders' equity
Common stock, $0.01 par value, 150,000,000 shares authorized 39,513,351 shares issued and 35,954,925 outstanding at September 30, 2012 and 39,439,115 shares issued and 37,907,575 outstanding at December 31, 2011	395	394
Additional paid-in capital	100,834	98,929
Retained earnings	161,965	93,950
Treasury stock, 3,558,426 and 1,531,540 shares at September 30, 2012 and December 31, 2011, respectively	(34,730)	(11,793)
Accumulated other comprehensive loss	(21,080)	(14,810)
Total stockholders' equity	207,384	166,670
Total liabilities and stockholders' equity	$ 692,773	$ 602,675