Long-Term Debt (Details) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Total debt
Long-term debt	$ 58,828	$ 58,828
Amounts payable within one year	0	0
Long-term debt, noncurrent	58,828	58,828
Term loan [Member]
Total debt
Long-term debt	57,750	57,750
Revolving credit facility [Member]
Total debt
Long-term debt	0	0
Secured debt of affiliate [Member]
Total debt
Long-term debt	$ 1,078	$ 1,078