Accumulated Other Comprehensive Income (Loss) Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance January 1,	$ (190,435)	$ (152,193)
Other comprehensive income (loss) before reclassifications	2,073	(12,700)
Amounts reclassified from accumulated other comprehensive income (net of tax $(7,047) and $(7,524))	11,068	11,819
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	(7,047)	(7,524)
Actuarial gain (loss), (net of tax $12,292 and $23,785)	(19,306)	(37,361)
Net Unamortized Gain (Loss) Arising During Period, Tax	12,292	23,785
Net current-period other comprehensive (loss) income	(6,165)	(38,242)
Ending Balance December 31,	(196,600)	(190,435)
Foreign Currency
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance January 1,	(12,416)	284
Other comprehensive income (loss) before reclassifications	2,073	(12,700)
Amounts reclassified from accumulated other comprehensive income (net of tax $(7,047) and $(7,524))	0	0
Actuarial gain (loss), (net of tax $12,292 and $23,785)	0	0
Net current-period other comprehensive (loss) income	2,073	(12,700)
Ending Balance December 31,	(10,343)	(12,416)
Pension and Other Postretirement Benefits
Accumulated Other Comprehensive Income (Loss), Net of Tax [Roll Forward]
Beginning Balance January 1,	(178,019)	(152,477)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassified from accumulated other comprehensive income (net of tax $(7,047) and $(7,524))	11,068	11,819
Actuarial gain (loss), (net of tax $12,292 and $23,785)	(19,306)	(37,361)
Net current-period other comprehensive (loss) income	(8,238)	(25,542)
Ending Balance December 31,	$ (186,257)	$ (178,019)