Accumulated Other Comprehensive Loss (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning balance	$ (89,802)	$ (126,443)
Amounts reclassified from accumulated other comprehensive loss, Interest rate swap, net of tax of $142 and $148 in 2016 and 2015, respectively	242	237
Amounts reclassified from accumulated other comprehensive loss, Interest rate swap, tax	142	148
Amounts reclassified from accumulated other comprehensive loss, Actuarial gain (loss), net of tax of $(2,353) and $21,298 in 2016 and 2015, respectively	(3,787)	34,078
Amounts reclassified from accumulated other comprehensive loss, Actuarial gain (loss), tax	(2,353)	21,298
Net current-period other comprehensive income (loss)	(3,545)	34,315
Amounts reclassified from accumulated other comprehensive loss, Impact of spin-off, net of tax of $1,517		2,326
Amounts reclassified from accumulated other comprehensive loss, Impact of spin-off, tax	0	1,517
Accumulated other comprehensive loss, ending balance	(93,347)	(89,802)
Gains and Losses on Derivatives
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning balance	(242)	(479)
Amounts reclassified from accumulated other comprehensive loss, Interest rate swap, net of tax of $142 and $148 in 2016 and 2015, respectively	242	237
Amounts reclassified from accumulated other comprehensive loss, Actuarial gain (loss), net of tax of $(2,353) and $21,298 in 2016 and 2015, respectively	0	0
Net current-period other comprehensive income (loss)	242	237
Amounts reclassified from accumulated other comprehensive loss, Impact of spin-off, net of tax of $1,517		0
Accumulated other comprehensive loss, ending balance	0	(242)
Defined Benefit Pension Items
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning balance	(89,740)	(125,877)
Amounts reclassified from accumulated other comprehensive loss, Interest rate swap, net of tax of $142 and $148 in 2016 and 2015, respectively	0	0
Amounts reclassified from accumulated other comprehensive loss, Actuarial gain (loss), net of tax of $(2,353) and $21,298 in 2016 and 2015, respectively	(3,936)	33,825
Net current-period other comprehensive income (loss)	(3,936)	33,825
Amounts reclassified from accumulated other comprehensive loss, Impact of spin-off, net of tax of $1,517		2,312
Accumulated other comprehensive loss, ending balance	(93,676)	(89,740)
Other
Accumulated Other Comprehensive Income (Loss) [Roll Forward]
Accumulated other comprehensive loss, beginning balance	180	(87)
Amounts reclassified from accumulated other comprehensive loss, Interest rate swap, net of tax of $142 and $148 in 2016 and 2015, respectively	0	0
Amounts reclassified from accumulated other comprehensive loss, Actuarial gain (loss), net of tax of $(2,353) and $21,298 in 2016 and 2015, respectively	149	253
Net current-period other comprehensive income (loss)	149	253
Amounts reclassified from accumulated other comprehensive loss, Impact of spin-off, net of tax of $1,517		14
Accumulated other comprehensive loss, ending balance	$ 329	$ 180