Basis of Presentation and Summary of Significant Accounting Policies - Share Repurchase Program (Details) - USD ($) $ / shares in Units, $ in Thousands, shares in Millions		1 Months Ended	3 Months Ended	6 Months Ended
	Nov. 15, 2018	Dec. 31, 2018	Mar. 31, 2019	Mar. 31, 2019	Nov. 13, 2018
Accounting Policies [Abstract]
Authorized amount repurchase of common stock					$ 50,000
Share repurchases	$ 16,500		$ 7,505	$ 24,004
Average price per share (in dollars per share)			$ 11.53	$ 10.89
Completed common stock repurchase (in shares)		1.6	0.7	2.2
Average price per share (in dollars per share)		$ 10.62
Remaining authorized repurchase amount			$ 26,000	$ 26,000