STOCK-BASED COMPENSATION PLAN (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended		6 Months Ended		12 Months Ended
	Jan. 31, 2015	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of options granted				0	0
Fair value per share (in dollars per share)	$ 24.40	$ 26.10		$ 24.40		$ 24.40
Expected volatility, measurement period				3 years
Service period of shares (in years)				3 years
Cost		$ 697	$ 744	$ 1,682	$ 1,483
Capitalized		(87)	(70)	(178)	(140)
Net Expense		610	674	$ 1,504	$ 1,343
Unrecognized compensation cost of awards granted under the plan		$ 4,600
Weighted average period over which unrecognized compensation cost is to be recognized (in years)				2 years
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-beginning balance (in dollars per share)	$ 24.40			$ 24.40
Weighted average fair value nonvested shares-granted during the period (in dollars per share)				28.69
Weighted average fair value nonvested shares-cancelled/forfeited during the period (in dollars per share)				26.56
Weighted average fair value nonvested shares-vested during the period (in dollars per share)				27.26
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 26.10		$ 26.10		$ 24.40
Officers and Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares granted				159,416	136,906
The range of the actual amount of shares that ultimately vest of the original share units granted				0% to 200%
Vesting period of shares (in years)				3 years
Shares outstanding (in shares)	223,876	317,760		223,876		223,876
Cost		$ 511	586	$ 1,310	$ 1,167
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, beginning balance (in shares)	223,876			223,876
Granted (in shares)				159,416	136,906
Cancelled/Forfeited (in shares)				(65,532)
Vested (in shares)				0
Nonvested shares outstanding, ending balance (in shares)		317,760		317,760		223,876
Additional disclosures [Abstract]
Number of shares awarded during the period				0		0
Officers and Key Employees | 2013 - TSR
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares outstanding (in shares)		45,593		45,593
Fair value per share (in dollars per share)		$ 22.19		$ 22.19
Expected volatility				21.10%
Risk-free interest rate				0.40%
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)		45,593		45,593
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 22.19		$ 22.19
Officers and Key Employees | 2013 - EPS
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares outstanding (in shares)		45,593		45,593
Fair value per share (in dollars per share)		$ 25.59		$ 25.59
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)		45,593		45,593
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 25.59		$ 25.59
Officers and Key Employees | 2014 - TSR
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares outstanding (in shares)		51,323		51,323
Fair value per share (in dollars per share)		$ 21.31		$ 21.31
Expected volatility				20.00%
Risk-free interest rate				0.80%
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)		51,323		51,323
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 21.31		$ 21.31
Officers and Key Employees | 2014 - EPS
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares outstanding (in shares)		51,323		51,323
Fair value per share (in dollars per share)		$ 27.22		$ 27.22
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)		51,323		51,323
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 27.22		$ 27.22
Officers and Key Employees | 2015 - TSR
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares outstanding (in shares)		34,696		34,696
Fair value per share (in dollars per share)		$ 26.31		$ 26.31
Expected volatility				16.00%
Risk-free interest rate				1.10%
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)		34,696		34,696
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 26.31		$ 26.31
Officers and Key Employees | 2015 - EPS, ROE, Time
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares outstanding (in shares)		89,232		89,232
Fair value per share (in dollars per share)		$ 29.47		$ 29.47
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)		89,232		89,232
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 29.47		$ 29.47
Director
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares granted				25,398	23,220
Vesting period of shares (in years)				12 months
Shares Vested, Directors		100.00%
Shares outstanding (in shares)	23,220	25,398		23,220		23,220
Cost		$ 186	$ 158	$ 372	$ 316
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, beginning balance (in shares)	23,220			23,220
Granted (in shares)				25,398	23,220
Cancelled/Forfeited (in shares)				0
Vested (in shares)				(23,220)
Nonvested shares outstanding, ending balance (in shares)		25,398		25,398		23,220
Additional disclosures [Abstract]
Fair value of shares issued				$ 700	$ 600
Director | 2015
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Shares outstanding (in shares)		25,398		25,398
Fair value per share (in dollars per share)		$ 29.34		$ 29.34
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Nonvested shares outstanding, ending balance (in shares)		25,398		25,398
Additional disclosures [Abstract]
Weighted average fair value nonvested shares-ending balance (in dollars per share)		$ 29.34		$ 29.34
Minimum | Officers and Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of actual amount of shares that ultimately vest of original share units granted				0.00%
Maximum | Officers and Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Percentage of actual amount of shares that ultimately vest of original share units granted				200.00%
Stock Appreciation Rights (SARs)
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares granted				0	0
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Granted (in shares)				0	0
Restricted Stock
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Return On Equity Award Threshold				7.00%
Restricted Stock | Officers and Key Employees
Deferred Compensation Arrangement with Individual, Share-based Payments [Line Items]
Number of shares granted	47,824
Vesting period of shares (in years)				3 years
Share-based Compensation Arrangement by Share-based Payment Award, Payout Limit, Percentage				100.00%
Restricted stock award activity, excluding accrued dividend equivalents [Roll Forward]
Granted (in shares)	47,824