CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Common Stock	Retained Earnings	Accumulated Other Comprehensive Loss	Treasury Stock	Noncontrolling Interest in VIE	Total
Balance at Sep. 30, 2018	$ 45,008	$ 801,834	$ (110,643)	$ (36,078)	$ 24,075
Balance (in shares) at Sep. 30, 2018						27,255
Increase (Decrease) in Stockholders' Equity
Net income (loss)		(6,587)			(4,027)	$ (6,587)
Other comprehensive income (loss), net of tax			(1,999)			$ (1,999)
Stock issued under equity incentive plans (in shares)						129
Purchase of common stock, value	(3,419)
Purchase of common stock (in shares)						(46)
Stock- based compensation	2,720
Cumulative effect of accounting standard adoption		19,834			4,655
Stock issued under equity offering, net, value	215,832
Stock issued under equity offering, net (in shares)						3,795
Other		2
Balance at Dec. 31, 2018	260,141	815,083	(112,642)	(36,078)	24,703
Balance (in shares) at Dec. 31, 2018						31,133
Balance at Sep. 30, 2019	274,472	862,948	(139,693)	(36,078)	18,919	$ 980,568
Balance (in shares) at Sep. 30, 2019						31,178
Increase (Decrease) in Stockholders' Equity
Net income (loss)		(20,575)			3,990	$ (20,575)
Other comprehensive income (loss), net of tax			9,344			$ 9,344
Stock issued under equity incentive plans (in shares)						149
Stock issued under employee stock purchase plans, value	1,169
Purchase of common stock, value	(3,621)
Purchase of common stock (in shares)						(53)
Stock- based compensation	4,477
Cumulative effect of accounting standard adoption		(824)
Balance at Dec. 31, 2019	$ 276,497	$ 841,549	$ (130,349)	$ (36,078)	$ 22,909	$ 974,528
Balance (in shares) at Dec. 31, 2019						31,274