Consolidated Statements of Partners' Capital (USD $) In Thousands, unless otherwise specified	Total	General partner	Class A limited partners	Accumulated other comprehensive loss
Balance at Mar. 31, 2012	$ 42,535	$ 81	$ 42,777	$ (323)
Allocation of net loss:
Allocation of net loss:	(797)		(797)
Other comprehensive income:
Change in pension and severance obligations	6			6
Balance at Jun. 30, 2012	41,744	81	41,980	(317)
Balance at Dec. 31, 2011	42,537	81	42,785	(329)
Allocation of net loss:
Allocation of net loss:	(805)		(805)
Other comprehensive income:
Change in pension and severance obligations	12			12
Balance at Jun. 30, 2012	41,744	81	41,980	(317)
Balance at Dec. 31, 2012	42,002	81	42,286	(365)
Allocation of net loss:
Allocation of net loss:	(1,779)		(1,779)
Cash distributions:
Cash distributions:	(150)		(150)
Other comprehensive income:
Change in pension and severance obligations	14			14
Balance at Jun. 30, 2013	40,087	81	40,357	(351)
Balance at Mar. 31, 2013	41,231	81	41,508	(358)
Allocation of net loss:
Allocation of net loss:	(1,151)		(1,151)
Other comprehensive income:
Change in pension and severance obligations	7			7
Balance at Jun. 30, 2013	$ 40,087	$ 81	$ 40,357	$ (351)