Stock-Based Compensation - Other Narrative (Details) (USD $) In Millions, except Share data, unless otherwise specified			12 Months Ended					0 Months Ended	12 Months Ended
	Mar. 31, 2014 Restricted Stock	Mar. 31, 2013 Restricted Stock	Mar. 31, 2014 LTIPs	Mar. 31, 2014 2011/2012 LTIP	Mar. 31, 2014 2013/2014 LTIP	Mar. 31, 2014 2013/2014 LTIP Restricted Stock	Mar. 31, 2014 2014/2015 LTIP	Mar. 04, 2010 Chief executive officer Performance Vesting Stock Options	Mar. 31, 2006 Chief executive officer Performance Vesting Stock Options	Mar. 31, 2014 Chief executive officer Restricted Stock	Mar. 31, 2014 Board of directors Restricted Stock	Mar. 31, 2013 Board of directors Restricted Stock	Mar. 31, 2013 Executive leadership Restricted Stock	Mar. 31, 2014 Executive leadership Restricted Stock 2 years	Mar. 31, 2014 Executive leadership Restricted Stock 3 years
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards exercised (in shares)									166,667
Weighted average exercise price of awards exercised (in dollars per share)									$ 24.15
Life of options after vesting									10 years
Number of awards voluntarily relinquished (in shares)								83,333
Concurrent grant, replacement award (in shares)								0
Vesting period						3 years					1 year	9 months	4 years	2 years	3 years
Portion of award that vests per year (as a percent)													25.00%	50.00%	50.00%
Period of restriction for sale of shares										90 days
Unrecognized compensation costs	$ 0.8	$ 1.8
Performance period			2 years
Shares issued under plan				224,000
Shares granted under plan					444,000		501,000