Share Based Awards (Details 2) (USD $)	12 Months Ended
	Mar. 31, 2013		Mar. 31, 2012		Mar. 31, 2011
Summary of stock options granted
Number of Share Granted	557,000		459,000		110,000
2005 Stock Options Plan [Member]
Summary of stock options granted
Number of Share Granted	556,500		459,400		110,000
2005 Stock Options Plan [Member] | January 23, 2013
Summary of stock options granted
Option Grant Date	Jan. 23, 2013
Number of Share Granted	40,000
Exercise Price Granted	20
Exercise of option grants	5 years	[1]
Option Grants Expires	Jan. 23, 2021
2005 Stock Options Plan [Member] | November 5, 2012
Summary of stock options granted
Option Grant Date	Nov. 05, 2012
Number of Share Granted	5,000
Exercise Price Granted	17.68
Exercise of option grants	5 years	[1]
Option Grants Expires	Nov. 05, 2020
2005 Stock Options Plan [Member] | September 25, 2012
Summary of stock options granted
Option Grant Date	Sep. 25, 2012
Number of Share Granted	20,000
Exercise Price Granted	18.42
Exercise of option grants	5 years	[1]
Option Grants Expires	Sep. 25, 2020
2005 Stock Options Plan [Member] | First Option May 24, 2012
Summary of stock options granted
Option Grant Date	May 24, 2012
Number of Share Granted	346,000
Exercise Price Granted	30
Exercise of option grants	5 years	[1]
Option Grants Expires	May 24, 2020
2005 Stock Options Plan [Member] | Second Option May 24, 2012
Summary of stock options granted
Option Grant Date	May 24, 2012
Number of Share Granted	30,000
Exercise Price Granted	30
Exercise of option grants	4 years	[1]
Option Grants Expires	May 24, 2020
2005 Stock Options Plan [Member] | May 23, 2012
Summary of stock options granted
Option Grant Date	May 23, 2012
Number of Share Granted	116,000
Exercise Price Granted	30
Exercise of option grants	5 years	[1]
Option Grants Expires	May 23, 2020
2005 Stock Options Plan [Member] | May 31, 2011
Summary of stock options granted
Option Grant Date			May 31, 2011
Number of Share Granted			459,400
Exercise Price Granted			43.04
Exercise of option grants			5 years	[1]
Option Grants Expires			May 31, 2019
2005 Stock Options Plan [Member] | November 29, 2010 [Member]
Summary of stock options granted
Option Grant Date					Nov. 29, 2010
Number of Share Granted					20,000
Exercise Price Granted					30
Exercise of option grants					5 years	[1]
Option Grants Expires					Nov. 29, 2018
2005 Stock Options Plan [Member] | August 3, 2010
Summary of stock options granted
Option Grant Date					Aug. 03, 2010
Number of Share Granted					10,000
Exercise Price Granted					30
Exercise of option grants					5 years	[1]
Option Grants Expires					Aug. 03, 2018
2005 Stock Options Plan [Member] | June 4, 2010 [Member]
Summary of stock options granted
Option Grant Date					Jun. 04, 2010
Number of Share Granted					50,000
Exercise Price Granted					30
Exercise of option grants					5 years	[1]
Option Grants Expires					Jun. 04, 2018
2005 Stock Options Plan [Member] | June 2, 2010 [Member]
Summary of stock options granted
Option Grant Date					Jun. 02, 2010
Number of Share Granted					30,000
Exercise Price Granted					29.31
Exercise of option grants					5 years	[1]
Option Grants Expires					Jun. 02, 2018

[1] Options vest in equal annual installments on each grant anniversary date beginning one year after the grant date.