Accumulated Other Comprehensive (Loss) Income - Summary of components of accumulated other comprehensive (loss) income (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		$ (17,833)	$ (10,115)
Change during the period
Before-tax amount		(196)	(12,039)
Tax (expense) benefit		(586)	3,984
Reclassification adjustment, net of taxes:
Realized loss on securities		144
Amortization of net loss	[1]	502	337
Total activity in period		(136)	(7,718)
Balance		(17,969)	(17,833)
Pension Adjustment
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		(16,246)	(9,760)
Change during the period
Before-tax amount		1,621	(10,745)
Tax (expense) benefit		$ (592)	3,922
Reclassification adjustment, net of taxes:
Realized loss on securities
Amortization of net loss	[1]	$ 502	337
Total activity in period		1,531	(6,486)
Balance		(14,715)	(16,246)
Unrealized Gain (Loss) On Securities
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		(98)	10
Change during the period
Before-tax amount		(16)	(170)
Tax (expense) benefit		6	$ 62
Reclassification adjustment, net of taxes:
Realized loss on securities		$ 144
Amortization of net loss	[1]
Total activity in period		$ 134	$ (108)
Balance		36	(98)
Foreign Currency Translation
Accumulated Other Comprehensive Income Loss [Roll Forward]
Balance		(1,489)	(365)
Change during the period
Before-tax amount		$ (1,801)	$ (1,124)
Tax (expense) benefit
Reclassification adjustment, net of taxes:
Realized loss on securities
Amortization of net loss	[1]
Total activity in period		$ (1,801)	$ (1,124)
Balance		$ (3,290)	$ (1,489)

[1] Reported as part of selling, general and administrative expenses.