Employee Benefit Plans Fair Values of Pension Plan Assets, Classified in the Fair Value Hierarchy (Details) (Pension Plans, USD $) In Thousands, unless otherwise specified	Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Total	$ 168,408		$ 187,150		$ 174,938
Fixed income securities
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fixed income securities	168,432	[1]	187,172	[2]
Accounts payable – pending trades	(24)		(22)
Total	168,408		187,150
Fixed income securities | Level 1
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fixed income securities	15,629	[1]	10,562	[2]
Fixed income securities | Level 2
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fixed income securities	152,803	[1]	176,610	[2]
Fixed income securities | Level 3
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Fixed income securities	$ 0	[1]	$ 0	[2]

[1] (1) Fixed income securities are comprised of corporate bonds (71%), government bonds (20%), government agencies securities (5%) and other fixed income securities (4%).

[2] (2) Fixed income securities are comprised of corporate bonds (75%), government bonds (16%), government agencies securities (6%) and other fixed income securities (3%).