EQUITY - Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended				3 Months Ended				12 Months Ended						114 Months Ended
	Jun. 30, 2020	Oct. 31, 2019	Aug. 31, 2018	Feb. 28, 2018	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Jun. 30, 2020
Share Repurchase Program
Stock repurchase amount authorized during period	$ 250,000	$ 250,000	$ 100,000	$ 150,000					$ 100,000	$ 100,000	$ 100,000	$ 100,000	$ 100,000	$ 100,000
Authorized amount	$ 1,400,000				$ 1,400,000										$ 1,400,000
Number of shares of common stock repurchased					992,159		100								15,771,049
Average price paid per share					$ 100.54		$ 104.75								$ 64.68
Total purchase price					$ 99,800	$ 119,500	$ 10	$ 35,000							$ 1,000