Fair Value Measurements (Narrative) (Details) (USD $)	9 Months Ended							9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2012 Designated as Hedging Instrument [Member]	Dec. 31, 2011 Designated as Hedging Instrument [Member]	Sep. 30, 2012 Credit Agreement [Member]	Jul. 16, 2010 Foreign Exchange Option [Member] Credit Agreement [Member]	Sep. 30, 2012 Interest Rate Swap [Member]	Sep. 30, 2011 Interest Rate Swap [Member]	Sep. 30, 2012 Interest Rate Swap [Member] Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member]	Dec. 31, 2011 Interest Rate Swap [Member] Designated as Hedging Instrument [Member] Other Noncurrent Liabilities [Member]	Sep. 30, 2012 Interest Rate Swap [Member] Minimum [Member]	Sep. 30, 2012 Interest Rate Swap [Member] Maximum [Member]
Fair Value Disclosures [Line Items]
(Losses)/gains recognized in income, net	$ 0	$ 600,000
Amount of credit facility						390,000,000
Notional amount							105,000,000
Fixed interest rate in swap							2.04%					2.00%	2.75%
Liability Derivative	5,150,000		4,251,000	5,150,000	4,251,000					5,150,000	4,251,000
Interest expense								$ 1,200,000	$ 1,400,000