Common And Preferred Stock (Schedule Of Repurchases Of Shares) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
Mar. 31, 2016	Mar. 31, 2015	Mar. 31, 2014
Series B 6.75% Convertible Perpetual Preferred Stock [Member]
Class of Stock [Line Items]
Number of shares repurchased	0	1,509	0
Weighted-average cost per share	$ 0.00	$ 992.27	$ 0
Stock Repurchased and Retired During Period, Cost Value	$ 0	$ 1,497	$ 0
Common Stock [Member]
Class of Stock [Line Items]
Number of shares repurchased	0	719,993	238,486
Cost of shares repurchased (in thousands of dollars)	$ 0	$ 31,227	$ 14,145
Weighted-average cost per share	$ 0.00	$ 43.37	$ 59.31

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 04
-Article 3

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 29, 30
-Article 5

Name:	us-gaap_StockRepurchasedDuringPeriodShares
Namespace Prefix:	us-gaap_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration