Schedule I (Parentheticals) (Details) - shares	Dec. 31, 2015	Dec. 31, 2014
Limited partners: Depositary units issued	131,481,059	123,103,414
Limited partners: Depositary units outstanding	131,481,059	123,103,414
Parent Company [Member]
Limited partners: Depositary units issued	131,481,059	123,103,414
Limited partners: Depositary units outstanding	131,481,059	123,103,414