Retirement And Other Employee Benefits (Summary Of Fair Value Hierarchy For Plan Assets) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Qualified Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	$ 618,293	$ 530,193
Qualified Pension Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	20,235	9,071
Qualified Pension Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	47,127	42,619
Qualified Pension Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	142,337	139,731
Qualified Pension Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	45,466	50,130
Qualified Pension Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	90,872	66,390
Qualified Pension Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	177,043	152,306
Qualified Pension Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	35,924	29,686
Qualified Pension Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	43,200	38,738
Qualified Pension Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	16,089	1,522
Retirement Health Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	43,236	39,390
Retirement Health Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	1,415	674
Retirement Health Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	3,296	3,166
Retirement Health Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	9,953	10,381
Retirement Health Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	3,179	3,724
Retirement Health Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	6,355	4,932
Retirement Health Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	12,380	11,316
Retirement Health Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	2,512	2,206
Retirement Health Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	3,021	2,878
Retirement Health Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	1,125	113
Level 1 [Member] | Qualified Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	189,464	182,350
Level 1 [Member] | Qualified Pension Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Qualified Pension Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	47,127	42,619
Level 1 [Member] | Qualified Pension Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	142,337	139,731
Level 1 [Member] | Qualified Pension Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Qualified Pension Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Qualified Pension Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Qualified Pension Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Qualified Pension Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Qualified Pension Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Retirement Health Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	13,249	13,547
Level 1 [Member] | Retirement Health Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Retirement Health Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	3,296	3,166
Level 1 [Member] | Retirement Health Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	9,953	10,381
Level 1 [Member] | Retirement Health Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Retirement Health Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Retirement Health Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Retirement Health Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Retirement Health Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 1 [Member] | Retirement Health Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 2 [Member] | Qualified Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	385,629	309,105
Level 2 [Member] | Qualified Pension Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	20,235	9,071
Level 2 [Member] | Qualified Pension Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 2 [Member] | Qualified Pension Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 2 [Member] | Qualified Pension Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	45,466	50,130
Level 2 [Member] | Qualified Pension Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	90,872	66,390
Level 2 [Member] | Qualified Pension Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	177,043	152,306
Level 2 [Member] | Qualified Pension Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	35,924	29,686
Level 2 [Member] | Qualified Pension Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 2 [Member] | Qualified Pension Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	16,089	1,522
Level 2 [Member] | Retirement Health Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	26,966	22,965
Level 2 [Member] | Retirement Health Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	1,415	674
Level 2 [Member] | Retirement Health Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 2 [Member] | Retirement Health Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 2 [Member] | Retirement Health Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	3,179	3,724
Level 2 [Member] | Retirement Health Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	6,355	4,932
Level 2 [Member] | Retirement Health Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	12,380	11,316
Level 2 [Member] | Retirement Health Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	2,512	2,206
Level 2 [Member] | Retirement Health Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 2 [Member] | Retirement Health Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	1,125	113
Level 3 [Member] | Qualified Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	43,200	38,738
Level 3 [Member] | Qualified Pension Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Qualified Pension Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Qualified Pension Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Qualified Pension Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Qualified Pension Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Qualified Pension Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Qualified Pension Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Qualified Pension Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	43,200	38,738
Level 3 [Member] | Qualified Pension Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	3,021	2,878
Level 3 [Member] | Retirement Health Benefits [Member] | Short-Term Investment Funds [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member] | Common Stock- U.S. Listed Small Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member] | Mutual Fund- U.S. Listed Large Cap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member] | Common/Collective Trust- Foreign Listed [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member] | U.S & Foreign Government And Government Agencies And Authorities [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member] | Corporate- U.S & Foreign Investment Grade [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member] | Corporate- U.S And Foreign High Yield [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	0	0
Level 3 [Member] | Retirement Health Benefits [Member] | Multi-Strategy Hedge Fund [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	3,021	2,878
Level 3 [Member] | Retirement Health Benefits [Member] | Interest Rate Swap [Member]
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	$ 0	$ 0