Fair Value Measurements (Narrative) (Details) (USD $)	Dec. 31, 2013	Dec. 31, 2012
Fair Value Measurements
Business Acquisition, Preacquisition Contingency, Amount of Settlement	$ 2,744,000
Debt Instrument [Line Items]
Long-term Debt gross	604,142,000	638,112,000
Fixed Interest Rate [Member]
Debt Instrument [Line Items]
Long-term Debt gross	348,958,000	354,105,000
Long-term Debt, Fair Value	364,349,000	379,036,000
Variable Interest Rate [Member]
Debt Instrument [Line Items]
Long-term Debt gross	255,184,000	284,007,000
Long-term Debt, Fair Value	$ 255,184,000	$ 284,007,000