Employee Benefits (Expected Future Benefit Payments - Other Postretirement Benefit Plans) (Details) (Other Postretirement Benefit Plans, Defined Benefit, USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Other Postretirement Benefit Plans, Defined Benefit
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year	$ 4,000
2013	3,749
2014	4,197
2015	4,698
2016	5,185
2017	5,682
2018-2022	$ 34,806