Employee Benefit Plans (Fair Value Of Pension Plan Assets By Asset Category) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012		Dec. 31, 2011
Pension Plans [Member]
Cash	$ 31		$ 164
U.S. government obligations	343		4,863
Government-sponsored enterprise obligations	6,930	[1]	9,749	[1]
State and municipal obligations	5,700		5,005
Agency mortgage-backed securities	3,000	[2]	4,480	[2]
Non-agency mortgage-backed securities	6,936		6,908
Asset-backed securities	7,125		8,085
Corporate bonds	23,962	[3]	22,700	[3]
International bonds	3,691		3,169
U.S. large-cap	22,400	[4]	13,928	[4]
U.S. mid-cap	12,600	[4]	8,250	[4]
U.S. small-cap	3,792	[4]	3,348	[4]
International developed markets	908	[4]	1,184	[4]
Emerging markets	916	[4]	1,569	[4]
Money market funds	3,500	[4]	3,826	[4]
Total	101,834		97,228
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
U.S. government obligations	438,759		357,155
Government-sponsored enterprise obligations	0		0
State and municipal obligations	0		0
Agency mortgage-backed securities	0		0
Non-agency mortgage-backed securities	0		0
Asset-backed securities	0		0
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member] | Pension Plans [Member]
Cash	31		164
U.S. government obligations	343		4,863
Government-sponsored enterprise obligations	0	[1]	0	[1]
State and municipal obligations	0		0
Agency mortgage-backed securities	0	[2]	0	[2]
Non-agency mortgage-backed securities	0		0
Asset-backed securities	0		0
Corporate bonds	0	[3]	0	[3]
International bonds	0		0
U.S. large-cap	22,400	[4]	13,928	[4]
U.S. mid-cap	12,600	[4]	8,250	[4]
U.S. small-cap	3,792	[4]	3,348	[4]
International developed markets	908	[4]	1,184	[4]
Emerging markets	916	[4]	1,569	[4]
Money market funds	3,500	[4]	3,826	[4]
Total	44,490		37,132
Significant Other Observable Inputs (Level 2) [Member]
U.S. government obligations	0		7,510
Government-sponsored enterprise obligations	471,574		315,698
State and municipal obligations	1,489,293		1,109,663
Agency mortgage-backed securities	3,380,955		4,106,059
Non-agency mortgage-backed securities	237,011		316,902
Asset-backed securities	3,167,394		2,693,143
Significant Other Observable Inputs (Level 2) [Member] | Pension Plans [Member]
Cash	0		0
U.S. government obligations	0		0
Government-sponsored enterprise obligations	6,930	[1]	9,749	[1]
State and municipal obligations	5,700		5,005
Agency mortgage-backed securities	3,000	[2]	4,480	[2]
Non-agency mortgage-backed securities	6,936		6,908
Asset-backed securities	7,125		8,085
Corporate bonds	23,962	[3]	22,700	[3]
International bonds	3,691		3,169
U.S. large-cap	0	[4]	0	[4]
U.S. mid-cap	0	[4]	0	[4]
U.S. small-cap	0	[4]	0	[4]
International developed markets	0	[4]	0	[4]
Emerging markets	0	[4]	0	[4]
Money market funds	0	[4]	0	[4]
Total	57,344		60,096
Significant Unobservable Inputs (Level 3) [Member]
U.S. government obligations	0		0
Government-sponsored enterprise obligations	0		0
State and municipal obligations	126,414		135,621
Agency mortgage-backed securities	0		0
Non-agency mortgage-backed securities	0		0
Asset-backed securities	0		0
Significant Unobservable Inputs (Level 3) [Member] | Pension Plans [Member]
Cash	0		0
U.S. government obligations	0		0
Government-sponsored enterprise obligations	0	[1]	0	[1]
State and municipal obligations	0		0
Agency mortgage-backed securities	0	[2]	0	[2]
Non-agency mortgage-backed securities	0		0
Asset-backed securities	0		0
Corporate bonds	0	[3]	0	[3]
International bonds	0		0
U.S. large-cap	0	[4]	0	[4]
U.S. mid-cap	0	[4]	0	[4]
U.S. small-cap	0	[4]	0	[4]
International developed markets	0	[4]	0	[4]
Emerging markets	0	[4]	0	[4]
Money market funds	0	[4]	0	[4]
Total	$ 0		$ 0

[1] This category represents bonds (excluding mortgage-backed securities) issued by agencies such as the Federal Home Loan Bank, the Federal Home Loan Mortgage Corp and the Federal National Mortgage Association.

[2] This category represents mortgage-backed securities issued by the agencies mentioned in (a).

[3] This category represents investment grade bonds of U.S. issuers from diverse industries.

[4] This category represents investments in individual common stocks and equity funds. These holdings are diversified, largely across the financial services, consumer goods, healthcare, technology, and energy sectors.