Retirement And Other Employee Benefits (Summary Of Fair Value Hierarchy For Plan Assets) (Details) - USD ($) $ in Thousands		Dec. 31, 2015	Dec. 31, 2014
Qualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	[1]	$ 838,697	$ 888,614
Qualified Pension Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		30,628	41,165
Qualified Pension Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		66,948	63,761
Qualified Pension Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		4,420	4,209
Qualified Pension Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		141,580	191,240
Qualified Pension Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		57,948	59,249
Qualified Pension Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		126,531	121,694
Qualified Pension Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		221,766	226,078
Qualified Pension Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		57,238	55,759
Qualified Pension Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		61,761	63,132
Qualified Pension Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		49,643	43,471
Qualified Pension Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		6,210	4,614
Qualified Pension Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		14,024	14,242
Retirement Health Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets	[1]	47,195	50,603
Retirement Health Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		1,723	2,344
Retirement Health Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,767	3,631
Retirement Health Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		249	240
Retirement Health Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		7,967	10,890
Retirement Health Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,261	3,374
Retirement Health Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		7,120	6,930
Retirement Health Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		12,479	12,874
Retirement Health Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,221	3,175
Retirement Health Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,475	3,595
Retirement Health Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		2,794	2,476
Retirement Health Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		350	263
Retirement Health Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		789	811
Level 1 | Qualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		212,948	259,210
Level 1 | Qualified Pension Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		66,948	63,761
Level 1 | Qualified Pension Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		4,420	4,209
Level 1 | Qualified Pension Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		141,580	191,240
Level 1 | Qualified Pension Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Qualified Pension Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		11,983	14,761
Level 1 | Retirement Health Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,767	3,631
Level 1 | Retirement Health Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		249	240
Level 1 | Retirement Health Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		7,967	10,890
Level 1 | Retirement Health Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 1 | Retirement Health Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Qualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		557,778	561,658
Level 2 | Qualified Pension Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		30,628	41,165
Level 2 | Qualified Pension Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Qualified Pension Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Qualified Pension Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Qualified Pension Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		57,948	59,249
Level 2 | Qualified Pension Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		126,531	121,694
Level 2 | Qualified Pension Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		221,766	226,078
Level 2 | Qualified Pension Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		57,238	55,759
Level 2 | Qualified Pension Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Qualified Pension Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		49,643	43,471
Level 2 | Qualified Pension Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Qualified Pension Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		14,024	14,242
Level 2 | Retirement Health Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		31,387	31,984
Level 2 | Retirement Health Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		1,723	2,344
Level 2 | Retirement Health Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Retirement Health Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Retirement Health Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Retirement Health Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,261	3,374
Level 2 | Retirement Health Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		7,120	6,930
Level 2 | Retirement Health Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		12,479	12,874
Level 2 | Retirement Health Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,221	3,175
Level 2 | Retirement Health Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Retirement Health Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		2,794	2,476
Level 2 | Retirement Health Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 2 | Retirement Health Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		789	811
Level 3 | Qualified Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		67,971	67,746
Level 3 | Qualified Pension Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		61,761	63,132
Level 3 | Qualified Pension Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Qualified Pension Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		6,210	4,614
Level 3 | Qualified Pension Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,825	3,858
Level 3 | Retirement Health Benefits | Short-term investment funds
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Common stock- U.S. listed small cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Preferred stock
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Mutual funds- U.S. listed large cap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Common/collective trust- foreign listed
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | U.S. & foreign government and government agencies and authorities
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Corporate- U.S. & foreign investment grade
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Corporate- U.S. & foreign high yield
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Multi-strategy hedge fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		3,475	3,595
Level 3 | Retirement Health Benefits | Commingled real estate fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		0	0
Level 3 | Retirement Health Benefits | Private equity fund
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		350	263
Level 3 | Retirement Health Benefits | Interest rate swap
Defined Benefit Plan Disclosure [Line Items]
Total financial assets		$ 0	$ 0

[1] The difference between the fair value of plan assets above and the amount used in determining the funded status is due to interest receivable which is not required to be included in the fair value hierarchy.