Employee Benefit Plans (Summary of Pension and Postretirement Plan Asset Allocation) (Details)	Dec. 31, 2015	Dec. 31, 2014
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	100.00%	100.00%
Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	100.00%	100.00%
Equity securities, available-for-sale | U.S. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	6.00%	7.00%
Equity securities, available-for-sale | U.S. | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	48.00%	57.00%
Equity securities, available-for-sale | International | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	5.00%	5.00%
Equity securities, available-for-sale | International | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	12.00%	5.00%
Fixed Maturities | U.S. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	67.00%	69.00%
Fixed Maturities | U.S. | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	32.00%	34.00%
Short-term investments | U.S. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	0.00%	0.00%
Short-term investments | U.S. | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	8.00%	4.00%
Real Estate | U.S. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	8.00%	6.00%
Real Estate | U.S. | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	0.00%	0.00%
Other | U.S. | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	14.00%	13.00%
Other | U.S. | Other Postretirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Percentage of asset class to total plan assets (actual)	0.00%	0.00%