Stockholders' Equity AOCI Change (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, before Reclassification Adjustments, Net of Tax		$ 0	$ 0
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Net of Tax	[1]	(456)	(1,022)
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax		(456)	(1,022)
Accumulated Other Comprehensive Loss, Pension and Other Postretirement Benefit Plans, Net of Tax		(16,729)	(26,100)	$ (17,185)	$ (27,122)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Gain (Loss) Arising During Period, Net of Tax		611	(4,314)
Other Comprehensive Income (loss), Foreign Currency Transaction and Translation Reclassification Adjustment from AOCI, Net of Tax	[1]	0	0
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax		611	(4,314)
Accumulated Other Comprehensive Loss, Foreign Currency Translation Adjustment, Net of Tax		(16,025)	(14,308)	$ (16,636)	$ (9,994)
Beginning Balance		(33,821)	(37,116)
Other comprehensive (loss) income before reclassifications		611	(4,314)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	[1]	456	1,022
Net current period other comprehensive income (loss)		1,067	(3,292)
Ending Balance		(32,754)	$ (40,408)
AOCI Attributable to Parent [Member]
Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax		(456)
Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax		$ 611

[1] See reclassifications from accumulated other comprehensive loss table for details of reclassification from accumulated other comprehensive loss for the three month periods ended March 31, 2016 and 2015, respectively.