Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 259,067	$ 256,947
Income tax refund receivable	576	3,903
Other current assets	1,322	3,232
Total current assets	260,965	264,082
Right-of-use asset	988
Income tax refund receivable, non-current	387	774
Investments in affiliates	90,184	24,574
Deferred tax assets	37,945	40,520
Other assets	341	350
Total assets	390,810	330,300
Current liabilities:
Accrued employment costs	2,611	2,573
Other current liabilities	2,883	1,495
Total current liabilities	5,494	4,068
Pension and other postretirement liabilities	17,447	15,167
Other liabilities	17,842	13,499
Total liabilities	40,783	32,734
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	(605,766)	(695,521)
Accumulated other comprehensive loss	(54,914)	(17,620)
Total shareholders' equity	350,027	297,566
Total liabilities and shareholders' equity	390,810	330,300
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)
Non-Voting Common Stock [Member]
Common Stock:
Common stock, 0.01 par value	$ 95	$ 95