Employee Benefit Plans (Fair Value of Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified								12 Months Ended
	Dec. 31, 2011 Pension Plans	Dec. 31, 2010 Pension Plans	Dec. 31, 2009 Pension Plans	Dec. 31, 2011 Pension Plans Level 1	Dec. 31, 2010 Pension Plans Level 1	Dec. 31, 2011 Pension Plans Level 2	Dec. 31, 2010 Pension Plans Level 2	Dec. 31, 2011 Pension Plans Level 3	Dec. 31, 2010 Pension Plans Level 3	Dec. 31, 2011 Pension Plans United States equities	Dec. 31, 2010 Pension Plans United States equities	Dec. 31, 2011 Pension Plans United States equities Level 1	Dec. 31, 2010 Pension Plans United States equities Level 1	Dec. 31, 2011 Pension Plans United States equities Level 2	Dec. 31, 2010 Pension Plans United States equities Level 2	Dec. 31, 2011 Pension Plans United States equities Level 3	Dec. 31, 2010 Pension Plans United States equities Level 3	Dec. 31, 2011 Pension Plans Global equities	Dec. 31, 2010 Pension Plans Global equities	Dec. 31, 2011 Pension Plans Global equities Level 1	Dec. 31, 2010 Pension Plans Global equities Level 1	Dec. 31, 2011 Pension Plans Global equities Level 2	Dec. 31, 2010 Pension Plans Global equities Level 2	Dec. 31, 2011 Pension Plans Global equities Level 3	Dec. 31, 2010 Pension Plans Global equities Level 3	Dec. 31, 2011 Pension Plans Fixed income	Dec. 31, 2010 Pension Plans Fixed income	Dec. 31, 2011 Pension Plans Fixed income Level 1	Dec. 31, 2010 Pension Plans Fixed income Level 1	Dec. 31, 2011 Pension Plans Fixed income Level 2	Dec. 31, 2010 Pension Plans Fixed income Level 2	Dec. 31, 2011 Pension Plans Fixed income Level 3	Dec. 31, 2010 Pension Plans Fixed income Level 3	Dec. 31, 2011 Pension Plans Alternative investments	Dec. 31, 2010 Pension Plans Alternative investments	Dec. 31, 2011 Pension Plans Alternative investments Level 1	Dec. 31, 2010 Pension Plans Alternative investments Level 1	Dec. 31, 2011 Pension Plans Alternative investments Level 2	Dec. 31, 2010 Pension Plans Alternative investments Level 2	Dec. 31, 2011 Pension Plans Alternative investments Level 3	Dec. 31, 2010 Pension Plans Alternative investments Level 3	Dec. 31, 2011 Pension Plans Cash and cash equivalents	Dec. 31, 2010 Pension Plans Cash and cash equivalents	Dec. 31, 2011 Pension Plans Cash and cash equivalents Level 1	Dec. 31, 2010 Pension Plans Cash and cash equivalents Level 1	Dec. 31, 2011 Pension Plans Cash and cash equivalents Level 2	Dec. 31, 2010 Pension Plans Cash and cash equivalents Level 2	Dec. 31, 2011 Pension Plans Cash and cash equivalents Level 3	Dec. 31, 2010 Pension Plans Cash and cash equivalents Level 3	Dec. 31, 2011 Postretirement Benefit Plans	Dec. 31, 2010 Postretirement Benefit Plans	Dec. 31, 2009 Postretirement Benefit Plans	Dec. 31, 2011 Postretirement Benefit Plans Level 1	Dec. 31, 2010 Postretirement Benefit Plans Level 1	Dec. 31, 2011 Postretirement Benefit Plans Level 2	Dec. 31, 2010 Postretirement Benefit Plans Level 2	Dec. 31, 2011 Postretirement Benefit Plans United States equities	Dec. 31, 2010 Postretirement Benefit Plans United States equities	Dec. 31, 2011 Postretirement Benefit Plans United States equities Level 1	Dec. 31, 2010 Postretirement Benefit Plans United States equities Level 1	Dec. 31, 2011 Postretirement Benefit Plans United States equities Level 2	Dec. 31, 2010 Postretirement Benefit Plans United States equities Level 2	Dec. 31, 2011 Postretirement Benefit Plans Global equities	Dec. 31, 2010 Postretirement Benefit Plans Global equities	Dec. 31, 2011 Postretirement Benefit Plans Global equities Level 1	Dec. 31, 2010 Postretirement Benefit Plans Global equities Level 1	Dec. 31, 2011 Postretirement Benefit Plans Global equities Level 2	Dec. 31, 2010 Postretirement Benefit Plans Global equities Level 2	Dec. 31, 2011 Postretirement Benefit Plans Fixed income	Dec. 31, 2010 Postretirement Benefit Plans Fixed income	Dec. 31, 2011 Postretirement Benefit Plans Fixed income Level 1	Dec. 31, 2010 Postretirement Benefit Plans Fixed income Level 1	Dec. 31, 2011 Postretirement Benefit Plans Fixed income Level 2	Dec. 31, 2010 Postretirement Benefit Plans Fixed income Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 195,659	$ 212,454	$ 167,653	$ 57,073	$ 69,351	$ 121,187	$ 116,262	$ 17,399	$ 26,841	$ 45,925	$ 54,926	$ 37,009	$ 44,566	$ 8,916	$ 10,360	$ 0	$ 0	$ 29,330	$ 35,432	$ 20,064	$ 24,785	$ 4,914	$ 5,560	$ 4,352	$ 5,087	$ 78,443	$ 69,878	$ 0	$ 0	$ 78,443	$ 69,878	$ 0	$ 0	$ 39,117	$ 48,442	$ 0	$ 0	$ 26,070	$ 26,688	$ 13,047	$ 21,754	$ 2,844	$ 3,776	$ 0	$ 0	$ 2,844	$ 3,776	$ 0	$ 0	$ 78,121	$ 80,118	$ 72,227	$ 46,737	$ 47,990	$ 31,384	$ 32,128	$ 33,649	$ 34,387	$ 33,649	$ 34,387	$ 0	$ 0	$ 13,088	$ 13,603	$ 13,088	$ 13,603	$ 0	$ 0	$ 31,384	$ 32,128	$ 0	$ 0	$ 31,384	$ 32,128
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of period	195,659	212,454	167,653	57,073	69,351	121,187	116,262	26,841	21,808	45,925	54,926	37,009	44,566	8,916	10,360	0	0	29,330	35,432	20,064	24,785	4,914	5,560	4,352	5,087	78,443	69,878	0	0	78,443	69,878	0	0	39,117	48,442	0	0	26,070	26,688	13,047	21,754	2,844	3,776	0	0	2,844	3,776	0	0	78,121	80,118	72,227	46,737	47,990	31,384	32,128	33,649	34,387	33,649	34,387	0	0	13,088	13,603	13,088	13,603	0	0	31,384	32,128	0	0	31,384	32,128
Unrealized losses								(752)	0
Unrealized gains relating to instruments held at the reporting date								635	1,242
Settlements								(9,604)	0
Purchases								279	3,791
Fair value of plan assets at end of period	$ 195,659	$ 212,454	$ 167,653	$ 57,073	$ 69,351	$ 121,187	$ 116,262	$ 17,399	$ 26,841	$ 45,925	$ 54,926	$ 37,009	$ 44,566	$ 8,916	$ 10,360	$ 0	$ 0	$ 29,330	$ 35,432	$ 20,064	$ 24,785	$ 4,914	$ 5,560	$ 4,352	$ 5,087	$ 78,443	$ 69,878	$ 0	$ 0	$ 78,443	$ 69,878	$ 0	$ 0	$ 39,117	$ 48,442	$ 0	$ 0	$ 26,070	$ 26,688	$ 13,047	$ 21,754	$ 2,844	$ 3,776	$ 0	$ 0	$ 2,844	$ 3,776	$ 0	$ 0	$ 78,121	$ 80,118	$ 72,227	$ 46,737	$ 47,990	$ 31,384	$ 32,128	$ 33,649	$ 34,387	$ 33,649	$ 34,387	$ 0	$ 0	$ 13,088	$ 13,603	$ 13,088	$ 13,603	$ 0	$ 0	$ 31,384	$ 32,128	$ 0	$ 0	$ 31,384	$ 32,128