Commitments and Contingencies - Operating Lease Commitments (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Schedule of Future Minimum Rental Commitments
Operating leases, rent expense	$ 1,423	$ 2,030	$ 1,960
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	3,221
2014	3,082
2015	2,443
2016	1,084
2017	716
Thereafter	4,170
Operating leases, future minimum payments due	14,716
Third Parties
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	1,110
2014	1,062
2015	1,005
2016	919
2017	633
Thereafter	4,170
Operating leases, future minimum payments due	8,899
Related Partnership
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2013	2,111
2014	2,020
2015	1,438
2016	165
2017	83
Thereafter	0
Operating leases, future minimum payments due	$ 5,817
Ownership percentage in partnership	50.00%