Employee Benefit Plans (Fair Value of Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified								12 Months Ended
	Dec. 31, 2012 Pension Plans	Dec. 31, 2011 Pension Plans	Dec. 31, 2010 Pension Plans	Dec. 31, 2012 Pension Plans Level 1	Dec. 31, 2011 Pension Plans Level 1	Dec. 31, 2012 Pension Plans Level 2	Dec. 31, 2011 Pension Plans Level 2	Dec. 31, 2012 Pension Plans Level 3	Dec. 31, 2011 Pension Plans Level 3	Dec. 31, 2012 Pension Plans United States equities	Dec. 31, 2011 Pension Plans United States equities	Dec. 31, 2012 Pension Plans United States equities Level 1	Dec. 31, 2011 Pension Plans United States equities Level 1	Dec. 31, 2012 Pension Plans United States equities Level 2	Dec. 31, 2011 Pension Plans United States equities Level 2	Dec. 31, 2012 Pension Plans United States equities Level 3	Dec. 31, 2011 Pension Plans United States equities Level 3	Dec. 31, 2012 Pension Plans Global equities	Dec. 31, 2011 Pension Plans Global equities	Dec. 31, 2012 Pension Plans Global equities Level 1	Dec. 31, 2011 Pension Plans Global equities Level 1	Dec. 31, 2012 Pension Plans Global equities Level 2	Dec. 31, 2011 Pension Plans Global equities Level 2	Dec. 31, 2012 Pension Plans Global equities Level 3	Dec. 31, 2011 Pension Plans Global equities Level 3	Dec. 31, 2012 Pension Plans Fixed income	Dec. 31, 2011 Pension Plans Fixed income	Dec. 31, 2012 Pension Plans Fixed income Level 1	Dec. 31, 2011 Pension Plans Fixed income Level 1	Dec. 31, 2012 Pension Plans Fixed income Level 2	Dec. 31, 2011 Pension Plans Fixed income Level 2	Dec. 31, 2012 Pension Plans Fixed income Level 3	Dec. 31, 2011 Pension Plans Fixed income Level 3	Dec. 31, 2012 Pension Plans Alternative investments	Dec. 31, 2011 Pension Plans Alternative investments	Dec. 31, 2012 Pension Plans Alternative investments Level 1	Dec. 31, 2011 Pension Plans Alternative investments Level 1	Dec. 31, 2012 Pension Plans Alternative investments Level 2	Dec. 31, 2011 Pension Plans Alternative investments Level 2	Dec. 31, 2012 Pension Plans Alternative investments Level 3	Dec. 31, 2011 Pension Plans Alternative investments Level 3	Dec. 31, 2012 Pension Plans Cash and cash equivalents	Dec. 31, 2011 Pension Plans Cash and cash equivalents	Dec. 31, 2012 Pension Plans Cash and cash equivalents Level 1	Dec. 31, 2011 Pension Plans Cash and cash equivalents Level 1	Dec. 31, 2012 Pension Plans Cash and cash equivalents Level 2	Dec. 31, 2011 Pension Plans Cash and cash equivalents Level 2	Dec. 31, 2012 Pension Plans Cash and cash equivalents Level 3	Dec. 31, 2011 Pension Plans Cash and cash equivalents Level 3	Dec. 31, 2012 Postretirement Benefit Plans	Dec. 31, 2011 Postretirement Benefit Plans	Dec. 31, 2010 Postretirement Benefit Plans	Dec. 31, 2012 Postretirement Benefit Plans Level 1	Dec. 31, 2011 Postretirement Benefit Plans Level 1	Dec. 31, 2012 Postretirement Benefit Plans Level 2	Dec. 31, 2011 Postretirement Benefit Plans Level 2	Dec. 31, 2012 Postretirement Benefit Plans United States equities	Dec. 31, 2011 Postretirement Benefit Plans United States equities	Dec. 31, 2012 Postretirement Benefit Plans United States equities Level 1	Dec. 31, 2011 Postretirement Benefit Plans United States equities Level 1	Dec. 31, 2012 Postretirement Benefit Plans United States equities Level 2	Dec. 31, 2011 Postretirement Benefit Plans United States equities Level 2	Dec. 31, 2012 Postretirement Benefit Plans Global equities	Dec. 31, 2011 Postretirement Benefit Plans Global equities	Dec. 31, 2012 Postretirement Benefit Plans Global equities Level 1	Dec. 31, 2011 Postretirement Benefit Plans Global equities Level 1	Dec. 31, 2012 Postretirement Benefit Plans Global equities Level 2	Dec. 31, 2011 Postretirement Benefit Plans Global equities Level 2	Dec. 31, 2012 Postretirement Benefit Plans Fixed income	Dec. 31, 2011 Postretirement Benefit Plans Fixed income	Dec. 31, 2012 Postretirement Benefit Plans Fixed income Level 1	Dec. 31, 2011 Postretirement Benefit Plans Fixed income Level 1	Dec. 31, 2012 Postretirement Benefit Plans Fixed income Level 2	Dec. 31, 2011 Postretirement Benefit Plans Fixed income Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 209,424	$ 195,659	$ 212,454	$ 65,689	$ 57,073	$ 129,235	$ 121,187	$ 14,500	$ 17,399	$ 50,979	$ 45,925	$ 41,907	$ 37,009	$ 9,072	$ 8,916	$ 0	$ 0	$ 34,479	$ 29,330	$ 23,782	$ 20,064	$ 10,697	$ 4,914	$ 0	$ 4,352	$ 78,806	$ 78,443	$ 0	$ 0	$ 78,806	$ 78,443	$ 0	$ 0	$ 42,159	$ 39,117	$ 0	$ 0	$ 27,659	$ 26,070	$ 14,500	$ 13,047	$ 3,001	$ 2,844	$ 0	$ 0	$ 3,001	$ 2,844	$ 0	$ 0	$ 87,189	$ 78,121	$ 80,118	$ 52,531	$ 46,737	$ 34,658	$ 31,384	$ 37,482	$ 33,649	$ 37,482	$ 33,649	$ 0	$ 0	$ 15,049	$ 13,088	$ 15,049	$ 13,088	$ 0	$ 0	$ 34,658	$ 31,384	$ 0	$ 0	$ 34,658	$ 31,384
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	209,424	195,659	212,454	65,689	57,073	129,235	121,187	17,399	26,841	50,979	45,925	41,907	37,009	9,072	8,916	0	0	34,479	29,330	23,782	20,064	10,697	4,914	0	4,352	78,806	78,443	0	0	78,806	78,443	0	0	42,159	39,117	0	0	27,659	26,070	14,500	13,047	3,001	2,844	0	0	3,001	2,844	0	0	87,189	78,121	80,118	52,531	46,737	34,658	31,384	37,482	33,649	37,482	33,649	0	0	15,049	13,088	15,049	13,088	0	0	34,658	31,384	0	0	34,658	31,384
Unrealized gains (losses)								992	(752)
Unrealized gains relating to instruments held at the reporting date								242	635
Settlements								(4,948)	(9,604)
Purchases								815	279
Fair value of plan assets at end of period	$ 209,424	$ 195,659	$ 212,454	$ 65,689	$ 57,073	$ 129,235	$ 121,187	$ 14,500	$ 17,399	$ 50,979	$ 45,925	$ 41,907	$ 37,009	$ 9,072	$ 8,916	$ 0	$ 0	$ 34,479	$ 29,330	$ 23,782	$ 20,064	$ 10,697	$ 4,914	$ 0	$ 4,352	$ 78,806	$ 78,443	$ 0	$ 0	$ 78,806	$ 78,443	$ 0	$ 0	$ 42,159	$ 39,117	$ 0	$ 0	$ 27,659	$ 26,070	$ 14,500	$ 13,047	$ 3,001	$ 2,844	$ 0	$ 0	$ 3,001	$ 2,844	$ 0	$ 0	$ 87,189	$ 78,121	$ 80,118	$ 52,531	$ 46,737	$ 34,658	$ 31,384	$ 37,482	$ 33,649	$ 37,482	$ 33,649	$ 0	$ 0	$ 15,049	$ 13,088	$ 15,049	$ 13,088	$ 0	$ 0	$ 34,658	$ 31,384	$ 0	$ 0	$ 34,658	$ 31,384