Goodwill (Details) $ in Thousands	3 Months Ended
	Dec. 31, 2017 USD ($)
Goodwill
Balance at the beginning of the period	$ 45,388
Translation adjustments	78
Balance at the end of the period	45,466
CAG
Goodwill
Balance at the beginning of the period	21,657
Translation adjustments	78
Balance at the end of the period	21,735
GovDeals
Goodwill
Balance at the beginning of the period	23,731
Translation adjustments	0
Balance at the end of the period	$ 23,731