Defined Benefit Plans Details Textual (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Stock Issued During Period, Value, Employee Benefit Plan	$ 3,428	$ 11,850	$ 4,877
Contribution to defined benefit pension plan (in shares)	66,000	183,000	88,200
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Accumulated Benefit Obligation	$ 1,000,000	$ 1,300,000
Defined Benefit Plan, Pension Plans with Accumulated Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	700,000	1,000,000
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Benefit Obligation	1,000,000	1,400,000
Defined Benefit Plan, Plans with Benefit Obligations in Excess of Plan Assets, Aggregate Fair Value of Plan Assets	700,000	1,100,000
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 34,900
Defined Benefit Plan, Ultimate Health Care Cost Trend Rate	6.00%
Defined Benefit Plan, Description of Direction and Pattern of Change for Assumed Health Care Cost Trend Rate	The rate was assumed to decrease gradually to 5.0% by 2021 for one the Company’s plans and to 4.5% by 2027 for the remaining plans and remain at those levels thereafter for benefits covered under the plans.
Defined Contribution Plan, Cost Recognized	$ 26,500	25,300	$ 21,500
All Plans [Member]
Stock Issued During Period, Value, Employee Benefit Plan	$ 3,400	$ 11,900