Debt (Details) CAD in Millions, AUD in Millions | 3 Months Ended | |
Dec. 31, 2017USD ($)periodletter_of_credit | Dec. 31, 2016USD ($) | Dec. 31, 2017AUDperiodletter_of_credit | Dec. 31, 2017CADperiodletter_of_credit |
Credit Agreement Expiring 2022 | | | | |
Debt Instrument [Line Items] | | | | |
Dividend payment restriction ratio (less than) | 2.5 | | | |
Total leverage ratio (less than) | 1 | | | |
Interest paid | $ 100,000 | $ 600,000 | | |
Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Number of letters of credit issued | letter_of_credit | 3 | | 3 | 3 |
Outstanding borrowings | $ 3,100,000 | | | |
Letters of Credit (Other than Revolving Credit Agreement) | | | | |
Debt Instrument [Line Items] | | | | |
Number of letters of credit issued | letter_of_credit | 1 | | 1 | 1 |
Outstanding borrowings | $ 1,000,000 | | | |
Atlantic Innovation Fund of Canada | | | | |
Debt Instrument [Line Items] | | | | |
Amount borrowed | $ 600,000 | | | CAD 0.8 |
Number of remaining quarterly installments | period | 18 | | 18 | 18 |
Line of Credit | Credit Agreement Expiring 2022 | | | | |
Debt Instrument [Line Items] | | | | |
Amount borrowed | $ 10,000,000 | | AUD 1.6 | |
Line of Credit | Credit Agreement Expiring 2022 | Revolving Credit Facility | | | | |
Debt Instrument [Line Items] | | | | |
Maximum borrowing capacity | 400,000,000 | | | |
Line of Credit | Credit Agreement Expiring 2022 | Bridge Loan | | | | |
Debt Instrument [Line Items] | | | | |
Maximum borrowing capacity | 5,000,000 | | | |
Line of Credit | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Maximum borrowing capacity | $ 50,000,000 | | | |
Minimum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Commitment fee percentage | 0.125% | | | |
Maximum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Commitment fee percentage | 0.275% | | | |
Base Rate | Minimum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Basis spread on variable rate | 0.00% | | | |
Base Rate | Maximum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Basis spread on variable rate | 0.75% | | | |
Eurocurrency Rate | Minimum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Basis spread on variable rate | 1.00% | | | |
Eurocurrency Rate | Maximum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Basis spread on variable rate | 1.75% | | | |
Index Rate | Minimum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Basis spread on variable rate | 1.00% | | | |
Index Rate | Maximum | Credit Agreement Expiring 2022 | Letters of Credit | | | | |
Debt Instrument [Line Items] | | | | |
Basis spread on variable rate | 1.75% | | | |