RETIREMENT PLANS: (Details 4)	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets (percent)	100.00%	100.00%
Employee Stock Ownership Plan
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets (percent)	100.00%	100.00%
Other Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets (percent)	3.00%	2.00%
Other Securities [Member] \| Employee Stock Ownership Plan
Defined Benefit Plan Disclosure [Line Items]
Percentage of plan assets (percent)	1.00%	0.00%
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum (percent)	40.00%
Target plan asset allocations range maximum (percent)	65.00%
Percentage of plan assets (percent)	68.00%	63.00%
Equity Securities \| Employee Stock Ownership Plan
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum (percent)	95.00%
Target plan asset allocations range maximum (percent)	99.00%
Percentage of plan assets (percent)	99.00%	100.00%
Debt securities
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum (percent)	35.00%
Target plan asset allocations range maximum (percent)	60.00%
Percentage of plan assets (percent)	29.00%	35.00%
Debt securities \| Employee Stock Ownership Plan
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum (percent)	0.00%
Target plan asset allocations range maximum (percent)	0.00%
Percentage of plan assets (percent)	0.00%	0.00%
Other Security Investments [Member]
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum (percent)	0.00%
Target plan asset allocations range maximum (percent)	10.00%
Other Security Investments [Member] \| Employee Stock Ownership Plan
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations range minimum (percent)	0.00%
Target plan asset allocations range maximum (percent)	5.00%

The percentage of plan assets during the period.

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- Definition

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+ References

No definition available.

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Target allocation maximum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

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Target allocation minimum percentage of investments of this type to total plan assets presented on a weighted average basis.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 5
-Subparagraph (c)(i)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e2446-114920

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