Debt (Details)	1 Months Ended	6 Months Ended	9 Months Ended	21 Months Ended
	May. 06, 2020 USD ($)	Jul. 03, 2015 USD ($)	Mar. 31, 2020 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2017 USD ($)	May. 06, 2015 USD ($)	Dec. 31, 2014 USD ($)	Nov. 20, 2012 USD ($)
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage		1.59%
Consolidated Senior Secured Indebtedness to Consolidated EBITDA, Ratio		3.5
Consideration for Permitted Acquisition under Credit Agreement		$ 125,000,000
Consolidated Interest Coverage Ratio		4.0
Consolidated Total Leverage Ratio		4
Minimum Liquidity Debt Covenant under Credit Agreement		50.00%
Credit Agreement Election [Member]
Debt Instrument [Line Items]
Consolidated Total Leverage Ratio		4.25
Revolving Credit Facility [Member] | JPMorgan Chase Bank NA as Administrative Agent Bank of America NA and Citizens Bank NA as Co-Syndication Agents [Member]
Debt Instrument [Line Items]
Long-term Debt, Gross		$ 64,400,000					$ 92,200,000
Line of Credit Facility, Remaining Borrowing Capacity		$ 345,200,000					248,600,000
Line of Credit Facility, Maximum Borrowing Capacity						$ 600,000,000		$ 400,000,000
Long-term Line of Credit						700,000,000.0
Revolving Credit Facility [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.175%
Revolving Credit Facility [Member] | Maximum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage		0.30%
Medium-term Notes [Member]
Debt Instrument [Line Items]
Long-term Line of Credit						$ 100,000,000
Medium-term Notes [Member] | Credit Agreement Election [Member]
Debt Instrument [Line Items]
Consolidated Senior Secured Indebtedness to Consolidated EBITDA, Ratio		3.75
Credit Agreement Election [Member] | JPMorgan Chase Bank NA as Administrative Agent Bank of America NA and Citizens Bank NA as Co-Syndication Agents [Member]
Debt Instrument [Line Items]
Long-term Line of Credit		$ 900,000,000
Line of Credit [Member] | JPMorgan Chase Bank NA as Administrative Agent Bank of America NA and Citizens Bank NA as Co-Syndication Agents [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		25,100,000					59,200,000
Line of Credit [Member] | New Zealand Ministry of Defense [Member] | JPMorgan Chase Bank NA as Administrative Agent Bank of America NA and Citizens Bank NA as Co-Syndication Agents [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount		$ 19,200,000					$ 54,500,000
Line of Credit [Member] | Minimum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage		1.25%
Line of Credit [Member] | Maximum [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Commitment Fee Percentage		2.00%
Foreign Subsidiary [Member] | Commercial Loan [Member] | Line of Credit [Member]
Debt Instrument [Line Items]
Equity Interest In Certain Foreign Subsidiaries		66.00%
Equity Interest In Domestic Subsidiaries		100.00%
Scenario, Forecast [Member] | Medium-term Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Final Periodic Payment, Principal	$ 65,000,000
Debt Instrument, Periodic Payment, Principal			$ 2,500,000	$ 1,875,000	$ 1,250,000