Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2013 Other Long-Term Obligations [Member]	Dec. 31, 2012 Other Long-Term Obligations [Member]	Mar. 31, 2013 Accrued Expenses [Member]	Dec. 31, 2012 Accrued Expenses [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration liability in other long-term obligations			$ 6,300,000	$ 5,900,000
Contingent consideration liability in accrued expenses					425,000	723,000
Other ssset impairment charges	$ 2,000	$ 0