Face (par) amount of debt instrument at time of issuance.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

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

Subsequent Events (Details) - $450 Million Unsecured Revolving Credit Facility - Revolving Credit Facility - USD ($)	Jul. 05, 2016	Jul. 21, 2015	Jun. 30, 2016	Dec. 31, 2015
Subsequent Event [Line Items]
Debt instrument face amount		$ 450,000,000	$ 450,000,000	$ 450,000,000
Debt instrument, extension, term		1 year
Subsequent Event
Subsequent Event [Line Items]
Debt instrument, extension, term	1 year