DIVIDEND REINVESTMENT AND COMMON STOCK REPURCHASE PLAN (Details) - USD ($) $ / shares in Units, $ in Thousands		12 Months Ended
	Jan. 07, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Class of Stock [Line Items]
Stock issued during period under dividend reinvestment plan (in shares)		42,872	43,650	44,575
Stock issued during period under dividend reinvestment plan, average price per share (in dollars per share)		$ 34.45	$ 33.99
Purchase of common stock (in shares)		1,459,148	0	443,426
Repurchase of common stock, cost		$ 47,193		$ 10,199
Subsequent Event
Class of Stock [Line Items]
Purchase of common stock (in shares)	40,852
Average cost per share (in usd per share)	$ 32.42