Borrowings Under Credit Facilities and Related Items (Tables)

6 Months Ended

Jun. 30, 2017

Borrowings Under Credit Facilities and Related Items (Tables) [Abstract]

Aggregate borrowings under the unsecured line of credit arrangements

		Three Months Ended June 30,				Six Months Ended June 30,
		2017		2016		2017		2016
Balance outstanding at quarter end(1)		$	385,000	$	745,000	$	385,000	$	745,000
Maximum amount outstanding at any month end		$	640,000	$	745,000	$	1,010,000	$	945,000
Average amount outstanding (total of daily
	principal balances divided by days in period)	$	561,626	$	623,077	$	678,343	$	647,060
Weighted average interest rate (actual interest
	expense divided by average borrowings outstanding)		1.94%		1.26%		1.87%		1.28%
(1) As of June 30, 2017, letters of credit in the aggregate amount of $32,456,000 have been issued, which reduces the borrowing capacity on the unsecured revolving credit facility.