Pensions and Other Postretirement Benefit Plans (Schedule of Funded Status of Plans) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 168,390	$ 173,434	$ 304,658
Benefit obligation	204,334	218,538	405,880
Funded status	(35,944)	(45,104)
Noncurrent asset	7,358	7,034
Current liability	(2,321)	(2,318)
Noncurrent liability	(40,981)	(49,820)
Net amount recognized	(35,944)	(45,104)
Net actuarial loss	73,908	84,784
Prior service cost/(credit)	866	405
Transition obligation		70
Net amount recognized	74,774	85,259
Other Postretirement Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets
Benefit obligation	61,108	84,368	79,009
Funded status	(61,108)	(84,368)
Noncurrent asset
Current liability	(5,056)	(5,547)
Noncurrent liability	(56,052)	(78,821)
Net amount recognized	(61,108)	(84,368)
Net actuarial loss	41,175	57,966
Prior service cost/(credit)	(44,364)	(40,329)
Transition obligation
Net amount recognized	$ (3,189)	$ 17,637