Accumulated Other Comprehensive Income Reclassifications in AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense), net	$ 38,270	$ (2,721)	$ 6,790
Provision for income taxes, investments	(298,396)	(398,902)	(331,747)
Total reclassifications for the period	475	209	(1,681)
Accumulated Defined Benefit Plans Adjustment, Net Prior Service Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of pension and other post-retirement items	0	(347)	(381)
Accumulated Defined Benefit Plans Adjustment, Net Gain (Loss) Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of pension and other post-retirement items	(2,663)	(577)	(2,331)
Accumulated Defined Benefit Plan Adjustment, Settlement Benefits Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of pension and other post-retirement items	(355)	0	0
Accumulated Defined Benefit Plans Adjustment Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Amortization of pension and other post-retirement items	(3,018)	(924)	(2,712)
Provision for income taxes, defined benefit plan	1,060	356	1,043
Total reclassifications for the period	(1,958)	(568)	(1,669)
Accumulated Net Investment Gain (Loss) Including Portion Attributable to Noncontrolling Interest [Member] | Reclassification out of Accumulated Other Comprehensive Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other income (expense), net	3,798	1,212	(19)
Provision for income taxes, investments	(1,365)	(435)	7
Income (Loss) from Continuing Operations, including portion attributable to noncontrolling interest	$ 2,433	$ 777	$ (12)