The Company (Details)	12 Months Ended
	Dec. 31, 2017 Property state
Variable Interest Entity [Line Items]
Number of consolidated properties | Property	175
Number of states in which entity has interests | state	37
LCIF [Member]
Variable Interest Entity [Line Items]
Limited partners, ownership interest	96.00%
Number of consolidated properties | Property	32
Number of states in which entity has interests | state	20