Employee Benefit Plans (Target and Actual Asset Allocation for Pension Plan by Asset Category) (Details) - Employee Pension Plans [Member]	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Pension Plan Assets
Target asset allocation (as a percent)	100.00%
Actual asset allocation (as a percent)	100.00%	100.00%
Cash [Member]
Pension Plan Assets
Target asset allocation (as a percent)	5.00%
Actual asset allocation (as a percent)	4.00%	4.00%
Equity Securities: Domestic [Member]
Pension Plan Assets
Target asset allocation (as a percent)	50.00%
Actual asset allocation (as a percent)	47.00%	61.00%
Equity Securities: International [Member]
Pension Plan Assets
Target asset allocation (as a percent)	25.00%
Actual asset allocation (as a percent)	28.00%	30.00%
Fixed Income Securities [Member]
Pension Plan Assets
Target asset allocation (as a percent)	20.00%
Actual asset allocation (as a percent)	21.00%	5.00%