CESSATION OF MINING AT LEASED PUEBLO GRAVEL SITE (Details)		3 Months Ended		12 Months Ended
	Sep. 30, 2016 USD ($) claim	Oct. 01, 2016 USD ($)	Sep. 27, 2014 T	Dec. 31, 2016 USD ($) T
CESSATION OF MINING AT LEASED PUEBLO GRAVEL SITE
Royalties recoverable pending outcome of litigation				$ 627,000
Pueblo Colorado gravel operations
CESSATION OF MINING AT LEASED PUEBLO GRAVEL SITE
Sand and gravel reserves (in tons) | T				50,000,000
Royalties recoverable pending outcome of litigation				$ 1,282,000
Write off of prepaid royalties		$ 632,000
Number of counterclaims | claim	3
Sand and gravel tons paid for | T			17,700,000
Overpayment of sand and gravel reserve | T			50,000,000
Pueblo Colorado gravel operations | Minimum [Member]
CESSATION OF MINING AT LEASED PUEBLO GRAVEL SITE
Amount of damages sought	$ 5,900,000