Subsequent Events (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended	9 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Oct. 11, 2017
Subsequent Event [Member]
Subsequent Event [Line Items]
Line Of Credit Facility Maturity Date Extensions	2
Subsequent Event [Member] | Common Stock [Member]
Subsequent Event [Line Items]
Common stock dividends declared per share	$ 0.20
Record date	Nov. 16, 2017
Dividends Payable, Date to be Paid	Nov. 30, 2017
London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]
Debt Instrument, Description of Variable Rate Basis		LIBOR
London Interbank Offered Rate (LIBOR) [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Description of Variable Rate Basis	LIBOR
Unsecured Line of Credit DRLP [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Current Borrowing Capacity		$ 1,200,000
Unsecured Line of Credit DRLP [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Line of Credit Facility, Current Borrowing Capacity			$ 1,200,000
Unsecured Line of Credit DRLP [Member] | London Interbank Offered Rate (LIBOR) [Member]
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate		0.93%
Unsecured Line of Credit DRLP [Member] | London Interbank Offered Rate (LIBOR) [Member] | Subsequent Event [Member]
Subsequent Event [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.875%