Goodwill and Other Intangible Assets (Rollforward of Other Intangible Assets) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Other Intangible Assets [Line Items]
Other intangible assets, gross carrying amount						$ 354,200
Accumulated amortization						(103,800)
Other Intangible Assets [Rollforward]
Other intangible assets, net, beginning balance				$ 250,373
Amortization expense		$ (7,300)	$ (5,800)	(14,600)	$ (10,400)
Currency translation adjustments, other intangible assets				(5,700)
Other intangible assets, net, ending balance		230,076		230,076
Customer Relationships and Backlog [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross carrying amount						199,800
Accumulated amortization						(90,300)
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance				109,500
Amortization expense				(13,600)
Currency translation adjustments, amortizing intangible assets				(1,200)
Other intangible assets, net, amortizing, ending balance		94,700		94,700
Other Amortizing Intangible Assets [Member]
Other Intangible Assets [Line Items]
Other intangible assets, amortizing, gross carrying amount	[1]					26,300
Accumulated amortization	[1]					(13,500)
Other Intangible Assets [Rollforward]
Other intangible assets, net, amortizing, beginning balance	[1]			12,800
Amortization expense	[1]			(1,000)
Currency translation adjustments, amortizing intangible assets	[1]			(200)
Other intangible assets, net, amortizing, ending balance	[1]	11,600		11,600
Trade Names [Member]
Other Intangible Assets [Line Items]
Other intangible assets, non-amortizing, carrying amount		34,800		34,800		34,800
Other Intangible Assets [Rollforward]
Other intangible assets, non-amortizing, beginning balance				34,800
Currency translation adjustments, non-amortizing intangible assets				0
Other intangible assets, non-amortizing, ending balance		34,800		34,800
Pre-Qualifications [Member]
Other Intangible Assets [Line Items]
Other intangible assets, non-amortizing, carrying amount		89,000		93,300		$ 93,300
Other Intangible Assets [Rollforward]
Other intangible assets, non-amortizing, beginning balance				93,300
Currency translation adjustments, non-amortizing intangible assets				(4,300)
Other intangible assets, non-amortizing, ending balance		$ 89,000		$ 89,000

[1] Consists principally of trade names and non-compete agreements.