NATURE OF OPERATIONS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Share Repurchase Program (Details) - USD ($)	1 Months Ended	6 Months Ended
	Jul. 31, 2016	Jun. 30, 2016	Jun. 30, 2015	Mar. 20, 2014	Oct. 28, 1999
Equity, Class of Treasury Stock [Line Items]
Repurchase authorization				$ 150,000,000	$ 150,000,000
Shares repurchased (shares)		400,000.0
Shares repurchased		$ 11,247,000	$ 7,803,000
Remaining authorization amount		$ 94,300,000
Subsequent Event
Equity, Class of Treasury Stock [Line Items]
Shares repurchased (shares)	200,000.0
Shares repurchased	$ 8,000,000