Retirement and Employee Benefit Plans (Amounts Recognized in Other Comprehensive Income) (Details) (USD $) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012
Pension Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	$ (5,038)
Amortization of net loss	1,219
Net actuarial loss arising during the year	(9,215)
Amortization of prior service cost	287
Tax effect	3,343
Plan amendments	(672)
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Total	(1,420)
Amortization of net loss	93
Net actuarial loss arising during the year	(2,525)
Amortization of transition obligation	64
Amortization of prior service cost	14
Tax effect	$ 934