Acquisitions (Narrative) (Details) (USD $)			0 Months Ended		3 Months Ended		1 Months Ended
	Oct. 31, 2014	Jul. 31, 2014	Sep. 30, 2014 Northern Technical [Member]	Sep. 30, 2014 Northern Technical [Member]	Oct. 31, 2014 Northern Technical [Member] Minimum [Member]	Oct. 31, 2014 Northern Technical [Member] Maximum [Member]	Nov. 30, 2014 Subsequent Event [Member] Northern Technical [Member]
Business Acquisition [Line Items]
Percentage of voting interest acquired				100.00%
Total consideration of transaction			$ 98,100,000
Amount of intangible assets acquired				8,257,000
Estimated useful life, years					6 months	7 years
Net tangible assets				32,200,000
Goodwill acquired	221,874,000	166,406,000		59,177,000
Period from purchase date the purchase price allocation is expected to be finalized						1 year
Working capital adjustment							$ 1,000,000