Employee Benefits (Changes in Fair Value Investment Real Estate - Other Postretirement Benefit Plans) (Details) (Other Postretirement Benefit Plans, Defined Benefit, USD $) In Thousands, unless otherwise specified				12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Limited Partnership Interest in Real Estate		Dec. 31, 2012 Limited Partnership Interest in Real Estate
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fair value of plan assets at end of prior year	$ 42,192	$ 36,510	$ 32,817	$ 1,605	[1]	$ 1,596
Unrealized gain in fair value				56		9
Fair value of plan assets at end of year	$ 42,192	$ 36,510	$ 32,817	$ 1,661	[1]	$ 1,605	[1]

[1] This investment is a commercial real estate partnership that purchases land, develops limited infrastructure, and sells it for commercial development. The Company is restricted from selling its partnership interest during the life of the partnership which is generally 5-7 years. Return of investment is realized as land is sold. The fair value of the limited partnership interest in real estate is based on the NAV of the partnership which reflects the appraised value of the land.