Related-Party Transactions (Amendments To The Share Repurchase Program For The Common Shares Approved For Repurchase) (Details)	Mar. 31, 2020 shares
Equity, Class of Treasury Stock [Line Items]
Common Shares Authorized for Repurchase, amount	30,000,000
Amendment Date, 09/21/2004 [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares Authorized for Repurchase, amount	5,000,000
Amendment Date, 07/21/2008 [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares Authorized for Repurchase, amount	5,000,000
Amendment Date, 02/24/2010 [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares Authorized for Repurchase, amount	5,000,000
Amendment Date, 02/22/2012 [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares Authorized for Repurchase, amount	5,000,000
Amendment Date, 05/15/2013 [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares Authorized for Repurchase, amount	5,000,000
Amendment Date, 11/19/2014 [Member]
Equity, Class of Treasury Stock [Line Items]
Common Shares Authorized for Repurchase, amount	5,000,000