Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Sep. 30, 2015	Dec. 31, 2014
Current Assets
Cash and cash equivalents	$ 83,687	$ 73,439
Short-term investments	42,081	46,919
Accounts receivable, less allowance for doubtful accounts of $21 and $136 at September 30, 2015 and December 31, 2014, respectively	86,176	88,502
Other receivables	20,858	33,295
Inventory, net	100,705	86,710
Prepaid expenses	5,935	5,129
Deferred tax assets, net	17,517	17,095
Total Current Assets	356,959	351,089
Property, plant and equipment, net	73,656	74,828
Deferred tax assets, net	23,341	17,694
Goodwill	3,492	3,492
Other assets	9,893	10,942
Long-term investments	204,513	280,649
Total Assets	671,854	738,694
Current Liabilities
Accounts payable	69,372	56,414
Unearned revenue	16,484	22,762
Accrued expenses	13,427	11,077
Accrued wages and benefits	14,842	13,855
Income tax payable, net	12,923	14,901
Total Current Liabilities	127,048	119,009
Non-current unearned revenue	8,685	10,948
Other non-current liabilities	29,680	30,924
Bonds payable	28,800	28,800
Total Liabilities	$ 194,213	$ 189,681
Commitments and contingencies (see Note 14)
Stockholders' Equity
Common stock, par value $0.01 per share; 200,000 shares authorized; 79,652 shares issued and 49,560 shares outstanding at September 30, 2015 and 79,652 shares issued and 53,431 shares outstanding at December 31, 2014	$ 797	$ 797
Additional paid-in capital	246,577	241,829
Accumulated other comprehensive loss	(10,238)	(75)
Retained earnings	905,928	907,751
Less treasury stock at cost: 30,092 and 26,221 shares at September 30, 2015 and December 31, 2014, respectively	(665,423)	(601,289)
Total Stockholders' Equity	477,641	549,013
Total Liabilities and Stockholders' Equity	$ 671,854	$ 738,694