Employee Benefit Plans Textuals (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended						12 Months Ended									12 Months Ended										1 Months Ended	12 Months Ended
	Dec. 31, 2011 plans	Dec. 31, 2010 plans	Dec. 31, 2009	Dec. 31, 2011 Qualified Defined Benefit Pension Plan [Member] plans	Dec. 31, 2011 Non-qualified Defined Benefit Pension Plan [Member] plans	Dec. 31, 2011 Supplemental Employee Retirement Plans [Member]	Dec. 31, 2011 Postretirement Medical [Member] employees	Dec. 31, 2011 Life Insurance Benefit [Member] employees	Dec. 31, 2011 Postretirement Life Insurance [Member] employees	Dec. 31, 2011 Pension Plans [Member] plans	Dec. 31, 2010 Pension Plans [Member]	Dec. 31, 2009 Pension Plans [Member]	Dec. 31, 2011 Other Postretirement Benefits [Member]	Dec. 31, 2010 Other Postretirement Benefits [Member]	Dec. 31, 2009 Other Postretirement Benefits [Member]	Dec. 31, 2011 Houly Pension Plan [Member] years	Dec. 31, 2011 Salaried Pension Plan [Member] years	Dec. 31, 2011 Minimum [Member]	Dec. 31, 2011 Minimum [Member] Supplemental Employee Retirement Plans [Member] years	Dec. 31, 2011 Ten Year Rate of Return [Member] Pension Plans [Member]	Dec. 31, 2010 Ten Year Rate of Return [Member] Pension Plans [Member]	Dec. 31, 2009 Ten Year Rate of Return [Member] Pension Plans [Member]	Dec. 31, 2011 Five Year Rate of Return [Member] Pension Plans [Member]	Dec. 31, 2010 Five Year Rate of Return [Member] Pension Plans [Member]	Dec. 31, 2009 Five Year Rate of Return [Member] Pension Plans [Member]	Jul. 31, 2009 Company Chairman [Member] Supplemental Employee Retirement Plans [Member]	Dec. 31, 2011 President and Chief Executive Officer [Member] Supplemental Employee Retirement Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Number of defined benefit plans	4	4		2	1					3
Age Requirement For Plant Participation																			60
Defined Benefit Plan, Required Employment Period																			8 years
Pension and Other Postretirement Benefit Expense																										$ 20,860
Pension and Other Postretirment, Additional SERP Benefit																											736
Defined Benefit Plan, Service Period Credit Upon Termination																											36 months
Defined Benefit Plan, Total Eligible Benefit																											20,546
Defined Benefit Plan, Increase in SERP Annuity																											7,122
Defined Benefit Plan, Number Of Participating Employees							334	200	458
Defined Benefit Plan, Employee Contribution Percentage							100.00%
Accumulated Other Comprehensive Income (Loss) not yet recognized										40,222	29,822		495	388
Benefit Plans, Number of Plans With Benefit Obligation in Excess of Fair Value of Plan Assets	3	2
Accumulated other comprehensive income (loss)	40,222	29,822	34,345							40,717	30,210	35,348	(495)	(388)	(1,003)
Accumulated benefit obligations in excess of aggregate projected benefit obligation	100,970	29,973
Accumulated benefit obligations in excess of aggregate accumulated benefit obligation	100,970	29,973
Accumulated benefit obligations in excess of aggregate fair value of plan assets	61,928	0
Actual Rate of Return On Plan Assets																				5.20%	4.80%	3.00%	2.90%	5.70%	3.50%
Actual Rate of Return Period (in years)																				10 years			5 years
Percentage of Excess in Projected Benefit Obligation and Fair Value Assets To Be Amortized																		10.00%
Period For Amortization of Benefit Plan Gains and Losses (in years)																15.77	17.24
Defined Benefit Plan, Estimated Future Employer Contributions in Next Fiscal Year										3,725
Defined Benefit Plan, Estimated Future Benefit Payments [Abstract]
2012						1,713	656			13,338
2013						22,584	656			33,810
2014						7,233	659			17,977
2015						0	662			10,397
2016						0	664			9,966
2017 — 2021						2,100	3,369			46,078
Defined Contribution Plan, Cost Recognized	$ 1,101	$ 1,068	$ 1,098