Supplemental Disclosure of Statement of Cash Flow Information (Details) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Other Significant Noncash Transactions [Line Items]
Cash and cash equivalents at beginning of period	$ 168,750,000	$ 168,750,000	$ 107,762,000	$ 86,637,000
Cash and cash equivalents at end of period		122,666,000	168,750,000	107,762,000
Restricted cash at beginning of period	8,497,000	8,497,000	4,394,000	31,142,000
Restricted cash at end of period		6,644,000	8,497,000	4,394,000
Cash, cash equivalents and restricted cash, at beginning of year	177,247,000	177,247,000	112,156,000	117,779,000
Cash, cash equivalents and restricted cash, at end of year		129,310,000	177,247,000	112,156,000
Interest paid		59,018,000	76,562,000	75,069,000
Income taxes paid, net		1,482,000	$ 2,025,000	2,340,000
Conveyed Interest
Other Significant Noncash Transactions [Line Items]
Mortgage loans on real estate, foreclosures				$ 12,616,000
Non-Recourse Mortgage
Other Significant Noncash Transactions [Line Items]
Face amount		$ 41,877,000
Richland, Washington
Other Significant Noncash Transactions [Line Items]
Extinguishment of debt	$ 110,000,000