Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
NET EARNINGS (LOSS)	$ 29,860	$ (19,628)	$ 40,874
Other comprehensive income (loss), net of tax	(5)	(29)	(37)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax	(1,059)	0	0
OTHER COMPREHENSIVE INCOME (LOSS):
Actuarial gain (loss) for retiree liabilities	(90,180)	130,330	(27,350)
Income tax (expense) or benefit	37	21	20
TOTAL COMPREHENSIVE INCOME (LOSS), net of tax	(23,198)	67,841	26,634
Pension Plans [Member]
Other comprehensive income (loss), net of tax	(50,119)	90,530	(10,976)
OTHER COMPREHENSIVE INCOME (LOSS):
Actuarial gain (loss) for retiree liabilities	(90,400)	129,856	(27,518)
Income tax (expense) or benefit	28,623	(51,622)	5,861
Post-Retirement Plans [Member]
Other comprehensive income (loss), net of tax	(1,875)	(3,032)	(3,227)
OTHER COMPREHENSIVE INCOME (LOSS):
Actuarial gain (loss) for retiree liabilities	220	474	168
Income tax (expense) or benefit	$ 1,071	$ 1,729	$ 1,724