Employee Benefit Plans (Pension Plans' Range Targets) (Details)	12 Months Ended
	Dec. 31, 2016
Equity Securities [Member]
Summary of target allocation percentage of assets
Target	42.00%
U.S. Equity [Member]
Summary of target allocation percentage of assets
Target	25.00%
International Equity [Member]
Summary of target allocation percentage of assets
Target	17.00%
Fixed Income, Money Market, Cash and Guaranteed Investment Contracts [Member]
Summary of target allocation percentage of assets
Target	58.00%
Fixed Income [Member]
Summary of target allocation percentage of assets
Target	56.00%
Money Market/Cash/Guaranteed Investments Contracts [Member]
Summary of target allocation percentage of assets
Target	2.00%