Senior Notes, Secured, and Unsecured Indebtedness - Revolving Line of Credit - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2016	Dec. 31, 2015	Mar. 27, 2015
Debt Instrument [Line Items]
Notes payable	$ 185,817,000	$ 175,181,000
Revolving Credit Facility
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 100,000,000
Additional capacity under accordion feature			125,000,000.0
Revolving Credit Facility | Revolving Credit Facility Agreement
Debt Instrument [Line Items]
Commitment fee percentage	0.50%
Outstanding letter of credit	$ 8,600,000	$ 8,600,000
Amended facility
Debt Instrument [Line Items]
Maximum borrowing capacity			130,000,000.0
Additional capacity under accordion feature			200,000,000.0
Minimum borrowing capacity			$ 50,000,000.0
Effective rate	3.50%	3.32%