Employee Benefit Plans Change in PBO and Assets and Reconciliations (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent liabilities	$ (95,654)	$ (159,582)
Pension Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Rollforward]
Projected benefit obligation at beginning of year	454,470	413,147
Service cost	8,452	8,407	6,782
Interest cost	16,682	17,284	18,087
Settlement loss	137	0
Actuarial (gain) loss	(44,786)	32,666
Plan amendments	0	0
Employee contributions	0	0
Benefits paid	(21,317)	(17,034)
Projected benefit obligation at end of year	413,638	454,470	413,147
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	320,699	295,655
Actual return on plan assets	42,285	41,729
Employer contributions	1,699	1,565
Employee contributions	0	0
Benefits paid	(21,317)	(17,034)
Other expense	(1,461)	(1,216)
Fair value of plan assets at end of year	341,905	320,699	295,655
Defined Benefit Plan, Funded Status of Plan [Abstract]
Net accrued benefit cost	(71,733)	(133,771)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent assets	3,583	0
Current liabilities	(1,776)	(1,702)
Noncurrent liabilities	(73,540)	(132,069)
Net amount recognized	(71,733)	(133,771)
Other Postretirement Benefit Plan, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Rollforward]
Projected benefit obligation at beginning of year	27,582	24,833
Service cost	1,056	918	673
Interest cost	937	956	972
Settlement loss	0	0
Actuarial (gain) loss	(3,206)	2,021
Plan amendments	(3,372)	0
Employee contributions	980	1,136
Benefits paid	(1,978)	(2,282)
Projected benefit obligation at end of year	21,999	27,582	24,833
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair value of plan assets at beginning of year	0	0
Actual return on plan assets	0	0
Employer contributions	998	1,146
Employee contributions	980	1,136
Benefits paid	(1,978)	(2,282)
Other expense	0	0
Fair value of plan assets at end of year	0	0	0
Defined Benefit Plan, Funded Status of Plan [Abstract]
Net accrued benefit cost	(21,999)	(27,582)
Defined Benefit Plan, Amounts Recognized in Balance Sheet [Abstract]
Noncurrent assets	0	0
Current liabilities	(1,071)	(1,256)
Noncurrent liabilities	(20,928)	(26,326)
Net amount recognized	$ (21,999)	$ (27,582)