Stockholders' Equity - Narrative - Distribution Reinvestment Plan (Details) - Distribution Reinvestment Plan [Member] - USD ($)	Sep. 30, 2017	Sep. 10, 2012	Jul. 23, 2009
Class of Stock [Line Items]
Share price (in dollars per share)		$ 9.73	$ 9.5
Sales commissions and dealer manager fees payable	$ 0

Amount payable to broker-dealers or clearing organizations for executing or clearing trades or orders.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 940
-SubTopic 20
-Section 25
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=68072869&loc=d3e41256-110953

Name:	us-gaap_CommissionsPayableToBrokerDealersAndClearingOrganizations
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant