Accumulated Other Comprehensive Income (Loss) (Summary Of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	$ 1,132,487	$ 1,176,572
Foreign currency translation adjustment of the Joint Venture	226	(2,593)
Balance	1,131,424	1,157,778
Foreign Currency Translation Adjustment [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(1,565)	1,268
Foreign currency translation adjustment of the Joint Venture	226	(2,593)
Balance	(1,339)	(1,325)
Cash Flow Hedge [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(1,691)	1,268
Change associated with current period hedging	(5,117)	1,206
Reclassification into earnings	(314)	(424)
Balance	(6,700)	2,540
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Balance	(3,256)	2,536
Foreign currency translation adjustment of the Joint Venture	226	(2,593)
Change associated with current period hedging	(5,117)	1,206
Reclassification into earnings	(314)	(424)
Balance	$ (8,039)	$ 1,215
ASU 2017-12 [Member] | Cash Flow Hedge [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Cumulative effect of accounting change of the Joint Venture				$ 490
ASU 2017-12 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Cumulative effect of accounting change of the Joint Venture				$ 490
ASU 2018-02 [Member] | Cash Flow Hedge [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Cumulative effect of accounting change of the Joint Venture			$ 422
ASU 2018-02 [Member] | Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated Other Comprehensive Income Loss [Line Items]
Cumulative effect of accounting change of the Joint Venture			$ 422