Annual report pursuant to Section 13 and 15(d)

Employee Benefit Plans - Target Allocation (Details)

v3.8.0.1
Employee Benefit Plans - Target Allocation (Details)
Dec. 31, 2017
U.S. | Qualified | Maximum | Pension Plan | Equity securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 60.00%
U.S. | Qualified | Maximum | Pension Plan | Debt securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 70.00%
U.S. | Qualified | Maximum | Pension Plan | Real Estate  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 10.00%
U.S. | Qualified | Maximum | Pension Plan | Other  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 5.00%
U.S. | Qualified | Minimum | Pension Plan | Equity securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 30.00%
U.S. | Qualified | Minimum | Pension Plan | Debt securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 40.00%
U.S. | Qualified | Minimum | Pension Plan | Real Estate  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 0.00%
U.S. | Qualified | Minimum | Pension Plan | Other  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 0.00%
U.S. | Nonqualified | Maximum | Other Pension Plan | Equity securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 5.00%
U.S. | Nonqualified | Maximum | Other Pension Plan | Debt securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 100.00%
U.S. | Nonqualified | Maximum | Other Pension Plan | Real Estate  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 5.00%
U.S. | Nonqualified | Maximum | Other Pension Plan | Other  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 5.00%
U.S. | Nonqualified | Minimum | Other Pension Plan | Equity securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 0.00%
U.S. | Nonqualified | Minimum | Other Pension Plan | Debt securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 95.00%
U.S. | Nonqualified | Minimum | Other Pension Plan | Real Estate  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 0.00%
U.S. | Nonqualified | Minimum | Other Pension Plan | Other  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 0.00%
Non-U.S. | Maximum | Pension Plan | Equity securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 35.00%
Non-U.S. | Maximum | Pension Plan | Debt securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 80.00%
Non-U.S. | Maximum | Pension Plan | Real Estate  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 15.00%
Non-U.S. | Maximum | Pension Plan | Other  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 25.00%
Non-U.S. | Minimum | Pension Plan | Equity securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 5.00%
Non-U.S. | Minimum | Pension Plan | Debt securities  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 40.00%
Non-U.S. | Minimum | Pension Plan | Real Estate  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 0.00%
Non-U.S. | Minimum | Pension Plan | Other  
Defined Benefit Plan, Assets, Target Allocations [Abstract]  
Target Allocation, Percentage 0.00%