Consolidated Balance Sheets (Unaudited) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Current Assets
Cash and cash equivalents	$ 72,558	$ 79,895
Short-term investments	52,458	43,188
Accounts receivable, less allowance for doubtful accounts of $— at March 31, 2017 and December 31, 2016	85,396	92,346
Other receivables	13,398	15,137
Income tax receivable, net		760
Inventory, net	112,774	105,117
Prepaid expenses and other current assets	17,816	16,459
Total Current Assets	354,400	352,902
Property, plant and equipment, net	83,514	84,469
Deferred tax assets, net	39,085	38,036
Goodwill	3,492	3,492
Other assets	12,274	12,234
Long-term investments	174,413	176,102
Total Assets	667,178	667,235
Current Liabilities
Accounts payable	74,300	77,342
Unearned revenue	16,969	16,326
Accrued expenses	15,035	12,434
Accrued wages and benefits	12,199	20,433
Income tax payable, net	3,126
Total Current Liabilities	121,629	126,535
Non-current unearned revenue	5,675	6,333
Other non-current liabilities	30,861	28,050
Bonds payable	26,800	26,800
Total Liabilities	184,965	187,718
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 48,321 shares outstanding at March 31, 2017 and 79,652 shares issued and 48,472 shares outstanding at December 31, 2016	797	797
Additional paid-in capital	254,965	252,957
Accumulated other comprehensive loss	(9,477)	(12,188)
Retained earnings	923,116	921,942
Less treasury stock at cost: 31,331 and 31,180 shares at March 31, 2017 and December 31, 2016, respectively	(687,188)	(683,991)
Total Stockholders’ Equity	482,213	479,517
Total Liabilities and Stockholders’ Equity	$ 667,178	$ 667,235