CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Current assets:
Cash and cash equivalents	$ 458,065	$ 454,092
Short-term investments, at cost which approximates market	15,898	14,178
Accounts receivable, net	205,917	193,328
Inventories	89,044	84,569
Prepaid expenses and other current assets	16,913	18,318
Total current assets	785,837	764,485
Property, plant and equipment, less accumulated depreciation and depletion - June 30, 2013 - $949,973; December 31,2012 - $944,283	308,803	317,669
Goodwill	64,592	65,829
Other assets and deferred charges	54,439	63,206
Total assets	1,213,671	1,211,189
Current liabilities:
Short-term debt	7,021	7,111
Current maturities of long-term debt	75,566	76,977
Accounts payable	110,765	98,371
Other current liabilities	63,446	67,639
Total current liabilities	256,798	250,098
Long-term debt	8,200	8,478
Accrued Pension and Post-Retirement Benefits	107,192	108,035
Other non-current liabilities	25,926	30,859
Total liabilities	398,116	397,470
Shareholders' equity:
Common stock	4,723	4,700
Additional paid-in capital	353,158	345,929
Retained earnings	1,065,249	1,032,869
Accumulated other comprehensive loss	(68,247)	(51,198)
Less common stock held in treasury	(562,040)	(541,889)
Total MTI shareholders' equity	792,843	790,411
Non-controlling interest	22,712	23,308
Total shareholders' equity	815,555	813,719
Total liabilities and shareholders' equity	$ 1,213,671	$ 1,211,189