Retirement Plans - Weighted Average Asset Allocations (Details) - Pension Plans, Defined Benefit [Member]	Dec. 31, 2015	Dec. 31, 2014
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocations	100.00%	100.00%
U.S. Equities securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocations	83.00%	82.00%
U.S. Debt securities [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocations	15.00%	17.00%
Cash [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Weighted average asset allocations	2.00%	1.00%