Retirement Benefits Plans (Details Textual) - USD ($)		3 Months Ended	12 Months Ended
	Jan. 01, 2011	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Defined Benefit Plan Disclosure [Line Items]
Estimated Change in Service and Interest Cost of Postretirement Benefits Expense and APBO Due to Change in Health Care Cost Trend Rates, Percent			1.00%	1.00%
Years of service, less than	10 years
Curtailment gain			$ 4,100,000	$ 2,500,000
Health care cost trend assumption increased health care cost trend rates (as a percent)			7.00%	7.50%
Health care cost trend assumption increased health care cost trend rates (as a percent)			5.00%
Estimated impact of one percent point change in assumed health care cost trend, less than			$ 100,000.0
Company's pretax income and the aggregate compensation levels of participating employees			6,500,000	$ 8,000,000	$ 7,400,000
Defined Benefit Plan
Defined Benefit Plan Disclosure [Line Items]
Settlement loss		$ 12,600,000	12,600,000	0	0
Benefit obligations			0	39,900,000	32,900,000
Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Benefit obligations			34,800,000	37,100,000	38,400,000
Curtailment gain			4,100,000	$ 2,500,000	$ 0
Amortization of net gains (losses)			800,000
Prior service benefit amortization			$ 700,000