CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Thousands	Total	Total Meta Stockholders' Equity [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss), Net of Tax [Member]	Treasury Stock [Member]	Non-controlling Interest [Member]
Balance at the beginning of the period at Sep. 30, 2015	$ 271,335	$ 271,335	$ 245	$ 170,586	$ 98,359	$ 2,455	$ (310)	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends declared on common stock	(4,389)	(4,389)			(4,389)
Issuance of common shares due to exercise of stock options	2,357	2,357	2	2,045			310
Issuance of common shares due to acquisition	11,501	11,501	8	11,493			0
Stock compensation	486	486		486
Net change in unrealized losses on securities, net of income taxes	20,465	20,465				20,465
Net income before noncontrolling interest	33,220	33,220			33,220
Balance at the end of the period at Sep. 30, 2016	334,975	334,975	255	184,610	127,190	22,920	0	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Adoption of Accounting Standards Update 2016-09				104	(104)
Cash dividends declared on common stock	(4,839)	(4,839)			(4,839)
Issuance of common shares due to exercise of stock options	650	650	0	650			0
Issuance of common shares due to restricted stock	12	12	12	0			0
Contingent consideration equity earnout due to acquisition	24,142	24,142		24,142
Issuance of common shares due to ESOP	1,174	1,174		1,174
Issuance of common shares due to acquisition	37,296	37,296	21	37,275
Shares repurchased for tax withholdings on stock compensation	(470)	(470)		(204)			(266)
Stock compensation	10,393	10,393		10,393
Net change in unrealized losses on securities, net of income taxes	(13,754)	(13,754)				(13,754)
Net income before noncontrolling interest	44,917	44,917			44,917
Balance at the end of the period at Sep. 30, 2017	434,496	434,496	288	258,144	167,164	9,166	(266)	0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cash dividends declared on common stock	(5,736)	(5,736)			(5,736)
Issuance of common shares due to exercise of stock options	148	148	1	147
Issuance of common shares due to restricted stock	4	4	4
Issuance of common shares due to ESOP	1,606	1,606	1	1,605
Issuance of common shares due to acquisition	295,766	295,766	99	295,667
Shares repurchased for tax withholdings on stock compensation	(2,598)	(2,598)		(875)			(1,723)
Stock compensation	11,123	11,123		11,123
Net change in unrealized losses on securities, net of income taxes	(42,277)	(42,277)				(42,277)
Net income before noncontrolling interest	52,293	51,620			51,620			673
Non-controlling interest due to acquisition	3,167							3,167
Distributions to non-controlling interest	(266)							(266)
Balance at the end of the period at Sep. 30, 2018	$ 747,726	$ 744,152	$ 393	$ 565,811	$ 213,048	$ (33,111)	$ (1,989)	$ 3,574