Benefit Plans Benefit Plans - Summary of Benefit Plan (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended			12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Pension Benefits [Member]
Change in benefit obligation
Benefit obligation at beginning of year				$ 673,711		$ 636,210
Service cost				11,616		11,446		10,854
Interest cost				27,597		31,831		31,491
Actuarial (gain) loss	(71,000)			(72,187)		96,043
Plan participant contributions				0		0
Medicare retiree drug subsidy reimbursements				0		0
Benefits paid				(26,185)		(23,909)
Curtailments				(45,858)		0
Settlements				(138,482)		(77,910)
Special termination benefits				38,733		0
Benefit obligation at end of year		673,711		468,945		673,711		636,210
Change in plan assets
Fair value of plan assets at beginning of year				473,097		485,489
Actual return on plan assets				34,560		58,560
Employer contributions				3,570		15,711
Plan participant contributions				0		0
Benefits paid				(26,185)		(23,909)
Settlements		(62,754)		(138,482)		(62,754)
Fair value of plan assets at end of year		473,097		346,560	[1]	473,097		485,489
Funded status		(200,614)		(122,385)		(200,614)
Amounts recognized in balance sheets
Noncurrent assets		0		80		0
Current liabilities		2,931		4,456		2,931
Noncurrent liabilities		197,683	[2]	118,010	[2]	197,683	[2]
Unrecognized net actuarial loss		(238,144)	[3]	(77,987)	[3]	(238,144)	[3]
Unrecognized prior service cost (benefit)		(1,679)		80	[3]	(1,679)
Net amount recognized		(39,209)		44,479		(39,209)
Change in accumulated other comprehensive income
Balance at beginning of year				(239,823)		(215,647)
Prior service cost (credit) recognized during the year				(313)		258
Net actuarial losses recognized during the year				14,469		16,777
Net actuarial gains (losses) occurring during the year				71,075		(63,118)
Settlements				20,156		(21,907)
Balance at end of year		(239,823)		(77,906)		(239,823)		(215,647)
Defined Benefit Plan, reduction to plan assets for anticipated lump sum payments in next fiscal year				15,817
Other Benefits [Member]
Change in benefit obligation
Benefit obligation at beginning of year				15,727		17,022
Service cost				0		0		0
Interest cost				628		814		930
Actuarial (gain) loss				(1,991)		(414)
Plan participant contributions				65		79
Medicare retiree drug subsidy reimbursements				215		166
Benefits paid				(1,559)		(1,940)
Curtailments				0		0
Settlements				0		0
Special termination benefits				0		0
Benefit obligation at end of year		15,727		13,085		15,727		17,022
Change in plan assets
Fair value of plan assets at beginning of year				0		0
Actual return on plan assets				0		0
Employer contributions				1,494		1,861
Plan participant contributions				65		79
Benefits paid				(1,559)		(1,940)
Settlements				0		0
Fair value of plan assets at end of year		0		0		0		0
Funded status		(15,727)		(13,085)		(15,727)
Amounts recognized in balance sheets
Noncurrent assets		0		0		0
Current liabilities		1,574		1,482		1,574
Noncurrent liabilities		14,153	[2]	11,604	[2]	14,153	[2]
Unrecognized net actuarial loss		(4,982)	[3]	(2,570)	[3]	(4,982)	[3]
Unrecognized prior service cost (benefit)		933		446		933
Net amount recognized		11,678		10,962		11,678
Change in accumulated other comprehensive income
Balance at beginning of year				(4,049)		(4,434)
Prior service cost (credit) recognized during the year				(488)		(517)
Net actuarial losses recognized during the year				423		488
Net actuarial gains (losses) occurring during the year				1,991		414
Settlements				0		0
Balance at end of year		(4,049)		(2,123)		(4,049)		(4,434)
Defined Benefit Plan Curtailment [Member] | Pension Benefits [Member]
Change in accumulated other comprehensive income
Prior service cost (credit) recognized during the year				2,075		0
Net actuarial losses recognized during the year				54,455		0
Defined Benefit Plan Curtailment [Member] | Other Benefits [Member]
Change in accumulated other comprehensive income
Prior service cost (credit) recognized during the year				0		0
Net actuarial losses recognized during the year				$ 0		$ 0

[1] Reflects anticipated distributions of $15,817 to be paid in 2014 related to the Company's voluntary early retirement program.

[2] Included in the consolidated balance sheets in pensions and other benefits and other post-retirement benefits are international plans.

[3] Represents amounts in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost.