Accumulated Other Comprehensive Income (Loss) (Reclassification) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	$ (107)		$ (101)		$ (1,374)		$ (867)
Income before income tax expense	28,537		19,781		65,517		37,493
Income tax benefit (expense)	(8,149)		(6,209)		(19,647)		(11,361)
Income from continuing operations	20,388		13,572		45,870		26,132
Reclassification out of Accumulated Other Comprehensive Income [Member] | Unrealized gain (loss) on derivative instruments [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Other income (expense), net	1				323
Income tax benefit (expense)	0				(113)
Income from continuing operations	1				210
Reclassification out of Accumulated Other Comprehensive Income [Member] | Amortization of defined benefit pension and other post-retirement benefit items [Member]
Reclassification out of Accumulated Other Comprehensive Income [Line Items]
Prior service costs	0	[1]	0	[1]	0	[1]	1,545
Actuarial losses	203	[1]	545	[1]	607	[1]	3,235
Income before income tax expense	203		545		607		4,780
Income tax benefit (expense)	(71)		(191)		(212)		(1,673)
Income from continuing operations	$ 132		$ 354		$ 395		$ 3,107

[1] These accumulated other comprehensive income components are included in the computation of net periodic pension cost. See Note 8 - "Pension Benefits and Other Postretirement Benefit Plans" for additional details.