Common Stock (Antidilutive Securities Excluded From Computation Of Earnings Per Share) (Details) - shares		3 Months Ended		12 Months Ended
		Mar. 31, 2019	Mar. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Performance shares payout based upon performance		0	0	0	0
Performance shares payout level		100.00%	100.00%	100.00%	100.00%
Restricted Stock
Antidilutive Securities Excluded from the Computation of Diluted Earnings Per Share, Amount		62,605	72,218	60,432	66,288
Performance Shares
Antidilutive Securities Excluded from the Computation of Diluted Earnings Per Share, Amount	[1]	43,652	45,977	22,234	11,494

[1] Certain performance shares were excluded from the computation of diluted earnings per share as no payouts would have been required based upon performance at the end of each corresponding period.