Basis Of Presentation (Narratives) (Details) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Mar. 31, 2016 USD ($) vie shares	Mar. 31, 2015 USD ($)	Sep. 30, 2015 shares	Dec. 31, 2014 shares	Dec. 31, 2013 shares	Dec. 31, 2012 shares	Dec. 31, 2011 shares	Dec. 31, 2015 USD ($)
Variable Interest Entity
Variable interest entities, count | vie	28
Deferred finance costs | $	$ 12,851
Common Stock
Variable Interest Entity
Stock repurchases in period, shares | shares	950,110		3,089,139	2,798,365	1,918,540	1,818,685	1,826,959
Treasury Stock
Variable Interest Entity
Prior period reclassification adjustment | $		$ (77,900)
Additional Paid-In-Capital
Variable Interest Entity
Prior period reclassification adjustment | $		$ (77,900)
Accounting Standards Update 2015-02
Variable Interest Entity
Variable interest entities, count | vie	15
Other assets | Accounting Standards Update 2015-03
Variable Interest Entity
Deferred finance costs | $								$ (12,800)
Loans receivables
Variable Interest Entity
Variable interest entities, count | vie	2
Non recourse debt and Term Loans | Accounting Standards Update 2015-03
Variable Interest Entity
Deferred finance costs | $								$ 12,500
Consolidated
Variable Interest Entity
Variable interest entities, count | vie	12
Equity Method
Variable Interest Entity
Variable interest entities, count | vie	14