Supplemental Disclosure of Statement of Cash Flow Information (Details) (USD $)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Other Significant Noncash Transactions [Line Items]
Interest paid	$ 100,080,000	$ 92,788,000	$ 101,262,000
Income taxes paid	859,000	4,666,000	1,018,000
Interests Sold [Member]
Other Significant Noncash Transactions [Line Items]
Real estate number of properties sold (in # of properties)		2
Real estate non-recourse mortgage debt assumed	30,140,000	40,356,000	8,921,000
Conveyed Interest [Member]
Other Significant Noncash Transactions [Line Items]
Properties with conveyed interest	1	4	2
Seller financing	9,900,000
Original debt conversion amount		$ 49,510,000	$ 12,409,000