DEBT (Summary Of The Balances Outstanding And Interest Rate Spread) (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Dec. 31, 2020
Short-term Debt
Line of Credit	$ 118,684	$ 133,053
Unsecured term loan	495,657	681,744
Term Loans:
Short-term Debt
Unsecured term loan	495,657	681,744
Deferred Loan Costs	(1,824)	(2,762)
$250 Million Senior Revolving Line Of Credit (Line of Credit) | Line of Credit
Short-term Debt
Line of Credit	118,684	133,053
$250 Million Term Loan (First Term Loan) | Term Loans:
Short-term Debt
Unsecured term loan	192,404	202,158
$300 Million Senior Term Loan Agreement (Second Term Loan) | Term Loans:
Short-term Debt
Unsecured term loan	278,846	292,983
$200 Million Senior Term Loan Agreement (Third Term Loan) | Term Loans:
Short-term Debt
Unsecured term loan	$ 26,231	$ 189,365
Minimum | $250 Million Senior Revolving Line Of Credit (Line of Credit) | Line of Credit
Short-term Debt
Basis spread on variable rate (percentage)	1.50%
Minimum | $250 Million Term Loan (First Term Loan) | Term Loans:
Short-term Debt
Basis spread on variable rate (percentage)	1.45%
Minimum | $300 Million Senior Term Loan Agreement (Second Term Loan) | Term Loans:
Short-term Debt
Basis spread on variable rate (percentage)	1.35%
Minimum | $200 Million Senior Term Loan Agreement (Third Term Loan) | Term Loans:
Short-term Debt
Basis spread on variable rate (percentage)	1.45%
Maximum | $250 Million Senior Revolving Line Of Credit (Line of Credit) | Line of Credit
Short-term Debt
Basis spread on variable rate (percentage)	2.25%
Maximum | $250 Million Term Loan (First Term Loan) | Term Loans:
Short-term Debt
Basis spread on variable rate (percentage)	2.20%
Maximum | $300 Million Senior Term Loan Agreement (Second Term Loan) | Term Loans:
Short-term Debt
Basis spread on variable rate (percentage)	2.00%
Maximum | $200 Million Senior Term Loan Agreement (Third Term Loan) | Term Loans:
Short-term Debt
Basis spread on variable rate (percentage)	2.20%