Employee Benefit Plans (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended	0 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Aug. 29, 2014
Change in projected benefit obligation:
Benefit obligation, January 1	$ 529,788	$ 583,294
Service cost	6,523us-gaap_DefinedBenefitPlanServiceCost	7,476us-gaap_DefinedBenefitPlanServiceCost
Interest cost	26,170us-gaap_DefinedBenefitPlanInterestCost	23,957us-gaap_DefinedBenefitPlanInterestCost
Actuarial (gain) loss	114,694	(67,063)
Regular benefits paid	(32,134)us-gaap_DefinedBenefitPlanBenefitsPaid	(17,876)us-gaap_DefinedBenefitPlanBenefitsPaid
Amendment	3,342	0
Acquisition	3,311	0
Benefit obligation, December 31	651,694	529,788
Accumulated benefit obligation	625,574	505,942
Change in plan assets:
Value of plan assets, January 1	404,335	336,534
Actual return on plan assets	43,662	62,701
Employer contributions	28,099	22,976
Benefits paid	(32,134)us-gaap_DefinedBenefitPlanBenefitsPaid	(17,876)us-gaap_DefinedBenefitPlanBenefitsPaid
Value of plan assets, December 31	443,962	404,335
Defined Benefit Pension Plan
Change in projected benefit obligation:
Benefit obligation, January 1	456,402	500,603
Service cost	4,952	5,527	4,350
Interest cost	23,068	20,897	20,945
Actuarial (gain) loss	113,410	(57,051)
Regular benefits paid	(14,752)	(13,574)
Benefit obligation, December 31	583,080	456,402	500,603
Accumulated benefit obligation	562,760	440,666
Change in plan assets:
Value of plan assets, January 1	404,335	336,534
Actual return on plan assets	43,662	62,701
Employer contributions	10,717	18,674
Benefits paid	(14,752)	(13,574)
Value of plan assets, December 31	443,962	404,335	336,534
Post-Retirement Medical Plan
Change in projected benefit obligation:
Benefit obligation, January 1	11,081	13,462
Service cost	985	947	817
Interest cost	574	512	569
Actuarial (gain) loss	(2,092)	(3,221)
Regular benefits paid	(508)	(619)
Amendment	(569)	0
Acquisition	3,311	0
Benefit obligation, December 31	12,782	11,081	13,462
Accumulated benefit obligation	12,782	11,081
Change in plan assets:
Employer contributions	508	619
Benefits paid	(508)	(619)
Post-Retirement Medical Plan \| J.P. Morgan Retirement Plan Services (RPS)
Change in projected benefit obligation:
Defined Benefit Plan, Number of Employees Covered				1,000
Post-Retirement Medical Plan \| Other Noncurrent Liabilities With Offset To Goodwill \| J.P. Morgan Retirement Plan Services (RPS)
Change in projected benefit obligation:
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)				3,311
Supplemental Executive Retirement Plan
Change in projected benefit obligation:
Benefit obligation, January 1	62,305	69,229
Service cost	586	1,002	991
Interest cost	2,528	2,548	2,912
Actuarial (gain) loss	3,376	(6,791)
Regular benefits paid	(16,874)	(3,683)
Amendment	3,911	0
Benefit obligation, December 31	55,832	62,305	69,229
Accumulated benefit obligation	50,032	54,195
Change in plan assets:
Employer contributions	16,874	3,683
Benefits paid	(16,874)	(3,683)
Supplemental Executive Retirement Plan \| Other Noncurrent Liabilities With Offset To Goodwill
Change in projected benefit obligation:
Defined Benefit Plan, Number of Employees Covered	1
Defined Benefit Plan, Benefit Obligation, Period Increase (Decrease)	$ 3,911

Defined Benefit Plan, Number of Employees Covered

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- Definition

For defined benefit pension plans, the actuarial present value of benefits (whether vested or nonvested) attributed by the pension benefit formula to employee service rendered before a specified date and based on employee service and compensation (if applicable) before that date. The accumulated benefit obligation differs from the projected benefit obligation in that it includes no assumption about future compensation levels. For plans with flat-benefit or nonpay-related pension benefit formulas, the accumulated benefit obligation and the projected benefit obligation are the same.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Accumulated Benefit Obligation

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- Definition

The difference between fair value of plan assets at the end of the period and the fair value at the beginning of the period, adjusted for contributions and payments of benefits during the period, and after adjusting for taxes and other expenses, as applicable.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Actual Return on Plan Assets (Component of Net Periodic Postretirement Benefit Cost)

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- Definition

Amount of gain (loss) related to change in benefit obligation resulting from changes in actuarial assumptions, for example, but not limited to, interest, mortality, employee turnover, salary, and temporary deviation from the substantive plan.

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- Definition

1) For defined benefit pension plans, the benefit obligation is the projected benefit obligation, which is the actuarial present value as of a date of all benefits attributed by the pension benefit formula to employee service rendered prior to that date. 2) For other postretirement defined benefit plans, the benefit obligation is the accumulated postretirement benefit obligation, which is the actuarial present value of benefits attributed to employee service rendered to a particular date.

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-Glossary Accumulated Postretirement Benefit Obligation

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Net increase or decrease in the plan benefit obligation during the reporting period.

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- Definition

The amount of payments made for which participants are entitled under a pension plan, including pension benefits, death benefits, and benefits due on termination of employment. Also includes payments made under a postretirement benefit plan, including prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. This item represents a periodic decrease to the plan obligations and a decrease to plan assets.

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-Glossary Postretirement Benefits

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The amount of increase in the benefit obligation attributed to business combinations.

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- Definition

The increase in the fair value of plan assets from contributions made by the employer.

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- Definition

Assets, usually stocks, bonds, and other investments, that have been segregated and restricted (usually in a trust) to provide benefits, at their fair value as of the measurement date. Plan assets include amounts contributed by the employer (and by employees for a contributory plan) and amounts earned from investing the contributions, less benefits paid. If a plan has liabilities other than for benefits, those non-benefit obligations may be considered as reductions of plan assets.

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The increase in a defined benefit pension plan's projected benefit obligation or a defined benefit postretirement plan's accumulated postretirement benefit obligation due to the passage of time.

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The amount of increase or decrease due to a change in the terms of an existing plan or the initiation of a new plan. A plan amendment may increase or decrease benefits, including those attributed to years of service already rendered.

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The actuarial present value of benefits attributed by the pension benefit formula to services rendered by employees during the period. The portion of the expected postretirement benefit obligation attributed to employee service during the period. The service cost component is a portion of the benefit obligation and is unaffected by the funded status of the plan.

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