Employee Benefit Plans (Details 6)	12 Months Ended
	Dec. 31, 2012
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	100.00%
Defined Benefit Plan, Debt Securities	100.00%
Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	23.00%
Defined Benefit Plan, Debt Securities	19.00%
Domestic equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	21.00%
Defined Benefit Plan, Debt Securities	17.00%
Non US developed equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	20.00%
Defined Benefit Plan, Debt Securities	20.00%
Alternative investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	19.00%
Defined Benefit Plan, Debt Securities	23.00%
Non US emerging equity securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	6.00%
Defined Benefit Plan, Debt Securities	7.00%
Hedge Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	5.00%
Defined Benefit Plan, Debt Securities	5.00%
Cash and Cash Equivalents [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	5.00%
Defined Benefit Plan, Debt Securities	7.00%
Fixed Income Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Target Allocation Percentage of Assets, Debt Securities	1.00%
Defined Benefit Plan, Debt Securities	2.00%