Employee Retirement Benefits (Weighted-Average Assumptions Used) (Details)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Minimum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Expected return on plan assets		7.50%
Maximum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Expected return on plan assets			8.00%
Benefit Obligations [Member] | Qualified Pension Plan [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Discount rate	4.20%	5.10%
Benefit Obligations [Member] | Qualified Pension Plan [Member] | Minimum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	2.75%	3.50%
Benefit Obligations [Member] | Qualified Pension Plan [Member] | Maximum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	3.25%	5.50%
Benefit Obligations [Member] | Supplemental Executive Retirement Plan (SERP) [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Discount rate	3.95%	4.75%
Benefit Obligations [Member] | Supplemental Executive Retirement Plan (SERP) [Member] | Minimum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	2.75%	3.50%
Benefit Obligations [Member] | Supplemental Executive Retirement Plan (SERP) [Member] | Maximum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	3.25%	5.50%
Net Periodic Benefit Cost [Member] | Qualified Pension Plan [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Discount rate	5.10%	5.85%	6.10%
Expected return on plan assets	7.50%	7.50%	8.00%
Net Periodic Benefit Cost [Member] | Qualified Pension Plan [Member] | Minimum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	3.50%	3.50%	4.00%
Net Periodic Benefit Cost [Member] | Qualified Pension Plan [Member] | Maximum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	5.50%	5.50%	6.00%
Net Periodic Benefit Cost [Member] | Supplemental Executive Retirement Plan (SERP) [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Discount rate	4.75%	5.55%	6.10%
Net Periodic Benefit Cost [Member] | Supplemental Executive Retirement Plan (SERP) [Member] | Minimum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	3.50%	3.50%	4.00%
Net Periodic Benefit Cost [Member] | Supplemental Executive Retirement Plan (SERP) [Member] | Maximum [Member]
Schedule of Benefit Obligations Weighted Average Assumptions [Line Items]
Rate of compensation increase	5.50%	5.50%	6.00%