Employee Benefit Plans (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Amounts recognized in consolidated balance sheets
Other current liabilities	$ 1,572,000	$ 1,437,000
Other long-term liabilities	39,194,000	75,466,000
Total	40,766,000	76,903,000
Amounts recognized in accumulated other comprehensive income (loss)
Net loss	32,279,000	54,431,000
Prior service cost	0	0
Total	32,279,000	54,431,000
Pension plans
Employee Benefits Plans
Expected benefit payments in next fiscal year	8,848,000
Change in benefit obligation
Benefit obligation at beginning of year	179,077,000	160,225,000
Service cost	343,000	467,000	457,000
Interest cost	7,237,000	7,841,000	8,118,000
Actuarial (gain) loss	(16,488,000)	18,745,000
Benefits paid	(8,799,000)	(8,201,000)
Benefit obligation at end of year	161,370,000	179,077,000	160,225,000
Change in plan assets
Fair value of plan assets at beginning of year	102,174,000	93,002,000
Actual return on plan assets	21,127,000	9,952,000
Contributions	6,102,000	7,421,000
Benefits paid	(8,799,000)	(8,201,000)
Fair value of plan assets at end of year	120,604,000	102,174,000	93,002,000
Funded status at end of year	(40,766,000)	(76,903,000)
Accumulated benefit obligation in excess of plan assets
Projected benefit obligation	161,370,000	179,077,000
Accumulated benefit obligation	160,340,000	177,442,000
Fair value of plan assets	120,604,000	102,174,000
Net Periodic Benefit Cost (Pre-tax)
Service cost	343,000	467,000	457,000
Interest cost	7,237,000	7,841,000	8,118,000
Expected return on plan assets	(7,383,000)	(6,733,000)	(7,022,000)
Amortization of prior service cost	0	4,000	49,000
Recognized actuarial loss	6,687,000	5,999,000	4,519,000
Net periodic benefit cost	6,884,000	7,578,000	6,121,000
Amounts Recognized in Other Comprehensive Income (Loss) (Pre-tax)
Net (gain) loss	(36,920,000)	9,548,000	17,222,000
Prior service cost	0	(4,000)	(49,000)
Total (benefit) cost recognized in other comprehensive loss	(36,920,000)	9,544,000	17,173,000
Net (benefit) cost recognized in net periodic benefit cost and other comprehensive (income) loss	(30,036,000)	17,122,000	23,294,000
Estimated net loss that will be amortized from accumulated other comprehensive loss into net periodic benefit cost in next fiscal year	3,700,000
Weighted-average assumptions used to determine net periodic benefit cost
Discount rate (as a percent)	4.15%	5.02%	5.62%
Expected return on plan assets (as a percent)	7.25%	7.25%	7.25%
Rate of compensation increase (as a percent)	3.00%	3.00%	4.00%
Weighted-average assumptions used to determine benefit obligations
Discount rate (as a percent)	4.94%	4.15%
Rate of compensation increase (as a percent)	3.00%	3.00%
Period considered for compounded returns	15 years
Frozen pension plan (funded)
Employee Benefits Plans
Contribution by employer in next fiscal year	5,600,000
Change in plan assets
Fair value of plan assets at beginning of year	102,174,000
Fair value of plan assets at end of year	120,604,000
Supplemental pension plan (unfunded)
Employee Benefits Plans
Expected benefit payments in next fiscal year	1,600,000
Accumulated benefit obligation in excess of plan assets
Accumulated benefit obligation	$ 24,100,000	$ 26,600,000