Stockholders' Equity - Reclassification out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended
		Mar. 31, 2016	Mar. 31, 2015
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains on investments		$ 56	$ 63
Tax effect		3,452	3,267
Loss from continuing operations		(6,959)	(1,972)
Reclassification out of Accumulated Other Comprehensive Income | Unrealized Gains on Investments
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Unrealized gains on investments		(20)	(27)
Tax effect		8	10
Loss from continuing operations		(12)	(17)
Reclassification out of Accumulated Other Comprehensive Income | Unrecognized Net Actuarial Loss and Prior Service Credit, Net
Reclassification Adjustment Out Of Accumulated Other Comprehensive Income [Line Items]
Recognized net actuarial (gain) loss	[1]	255	75
Amortization of prior service credit	[1]	(137)	(139)
Tax effect		(45)	(50)
Loss from continuing operations		$ 73	$ (114)

[1] Amount included in pension expense. Refer to Note 16 - Pension and Postretirement Benefits.