INTEREST AND OTHER INCOME (Details) $ in Millions	12 Months Ended
Dec. 31, 2015 USD ($)
INTEREST AND OTHER INCOME
Net proceeds from sale of surface lots	$ 5.6

Amount of gain (loss) on sale or disposal of assets, including but not limited to property plant and equipment, intangible assets and equity in securities of subsidiaries or equity method investee.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 360
-SubTopic 10
-Section 45
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=51824106&loc=d3e2443-110228

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration