Acquisitions (Details) (USD $) In Millions, unless otherwise specified			9 Months Ended
	Sep. 30, 2012	Jun. 06, 2012 TTS [Member]	Sep. 30, 2012 Elco [Member]	Mar. 31, 2012 Elco [Member]
Business Acquisition [Line Items]
Cash purchase price for company acquired		$ 248.1
Percentage of outstanding stock of Elco Filtration and Testing, Inc. acquired (in hundredths)				100.00%
Total purchase price of outstanding stock of Elco Filtration and Testing, Inc. acquired				61.5
Business combination, reason for business combination			Elco was purchased to strengthen the Company's wellhead product and service offerings and has been included in the DPS segment since the date of acquisition
Preliminary goodwill	$ 256.0