Employee Benefit Plans (Summary of the Activity in the SERP's Projected Benefit Obligation) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Benefit obligation:
Balance, January 1	$ 67,087	$ 53,972
Service cost	3,452	2,799
Interest cost	2,819	2,570
Benefits paid	1,423	1,317
Actuarial loss (gain)	(8,496)	9,063
Balance, December 31	63,439	67,087
Supplemental Executive Retirement Plan [Member]
Benefit obligation:
Balance, January 1	8,482	7,434
Service cost	144	115	89
Interest cost	335	307	295
Benefits paid	(236)	(236)	(236)
Actuarial loss (gain)	677	862
Balance, December 31		$ 8,482	$ 7,434