Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Current assets:
Cash and cash equivalents	$ 256,947	$ 255,139
Income taxes receivable	3,903	11,105
Other current assets	3,232	3,099
Total current assets	264,082	269,343
Income taxes receivable, non-current	774	1,550
Investments in affiliates	24,574	53,430
Deferred tax assets	40,520	50,016
Other assets	350	372
Total assets	330,300	374,711
Current liabilities:
Accrued employment costs	2,573	2,573
Other current liabilities	1,495	1,279
Total current liabilities	4,068	3,852
Pension and other postretirement liabilities	15,167	18,786
Long-term liabilities	13,499	61,475
Total liabilities	32,734	84,113
Commitments and contingencies
Shareholders' Equity:
Preferred stock, 0.01 par value; 10,000,000 shares authorized, no shares issued and outstanding
Common Stock:
Paid-in capital	1,019,988	1,019,988
Accumulated deficit	(695,521)	(682,831)
Accumulated other comprehensive loss	(17,620)	(37,278)
Total shareholders' equity	297,566	290,598
Total liabilities and shareholders' equity	330,300	374,711
Voting Common Stock [Member]
Common Stock:
Common stock, 0.01 par value	216	216
Treasury stock (at cost), 154,494 shares of voting common stock	(9,592)	(9,592)
Nonvoting Common Stock [Member]
Common Stock:
Common stock, 0.01 par value	$ 95	$ 95