XML 32 R22.htm IDEA: XBRL DOCUMENT v3.19.2
MARKETABLE SECURITIES (Summary of Changes in Fair Value of Company's Marketable Securities) (Details) - USD ($)
$ in Thousands
6 Months Ended 12 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Dec. 31, 2018
Investments, Debt and Equity Securities [Abstract]      
Balance at beginning of the period $ 56,662
Additions 2,551 59,407 71,783
Sale or maturity (23,773) (15,092)
Changes in fair value during the period 79 $ 436 (29)
Balance at end of the period $ 35,519   $ 56,662