Employee Benefit Plans (Fair Value Of Pension Plan Assets By Asset Category) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Pension Plans [Member]
U.S. government obligations	$ 1,290		$ 901
Government-sponsored enterprise obligations	1,259	[1]	2,512	[1]
State and municipal obligations	10,638		7,270
Agency mortgage-backed securities	1,762	[2]	1,744	[2]
Non-agency mortgage-backed securities	5,635		6,156
Asset-backed securities	5,776		5,985
Corporate bonds	34,264	[3]	36,345	[3]
U.S. large-cap	20,296	[4]	23,677	[4]
U.S. mid-cap	13,362	[4]	13,864	[4]
U.S. small-cap	3,590	[4]	4,331	[4]
International developed markets	3,377	[4]	857	[4]
Emerging markets	473	[4]	659	[4]
Money market funds	3,072	[4]	2,871	[4]
Total	104,794		107,172
Quoted Prices In Active Markets For Identical Assets (Level 1) [Member]
U.S. government obligations	501,407		505,696
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]
U.S. government obligations	1,290		901
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]
U.S. large-cap	20,296	[4]	23,677	[4]
U.S. mid-cap	13,362	[4]	13,864	[4]
U.S. small-cap	3,590	[4]	4,331	[4]
International developed markets	3,377	[4]	857	[4]
Emerging markets	473	[4]	659	[4]
Money market funds	3,072	[4]	2,871	[4]
Total	45,460		47,160
Significant Other Observable Inputs (Level 2) [Member]
U.S. government obligations	0		0
Government-sponsored enterprise obligations	963,127		741,766
State and municipal obligations	1,718,058		1,491,447
Agency mortgage-backed securities	2,593,708		2,772,338
Non-agency mortgage-backed securities	382,744		246,983
Asset-backed securities	3,091,993		2,844,071
Significant Other Observable Inputs (Level 2) [Member] | Pension Plans [Member]
U.S. government obligations	0		0
Government-sponsored enterprise obligations	1,259	[1]	2,512	[1]
State and municipal obligations	10,638		7,270
Agency mortgage-backed securities	1,762	[2]	1,744	[2]
Non-agency mortgage-backed securities	5,635		6,156
Asset-backed securities	5,776		5,985
Corporate bonds	34,264	[3]	36,345	[3]
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	59,334		60,012
Significant Unobservable Inputs (Level 3) [Member]
U.S. government obligations	0		0
Government-sponsored enterprise obligations	0		0
State and municipal obligations	95,143		127,724
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]
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]
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 issued in the U.S., primarily by domestic issuers, representing 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.