Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Loss [Member]	Retained Earnings/ (Accumulated Deficits) [Member] Cumulative effect of accounting standard adoption	Retained Earnings/ (Accumulated Deficits) [Member]	Parent [Member] Cumulative effect of accounting standard adoption	Parent [Member]	Noncontrolling Interest [Member]	Cumulative effect of accounting standard adoption	Total
BALANCE at Sep. 30, 2020	$ 1,570	$ 4,035,414	$ (918,674)		$ 174,248		$ 3,292,558	$ 120,986		$ 3,413,544
Increase (Decrease) in Stockholders' Equity
Net income					65,487		65,487	12,813		78,300
Other comprehensive income (loss)			22,938				22,938	190		23,128
Issuance of stock	19	16,995					17,014			17,014
Repurchases of stock	(121)	(22,942)			(568,608)		(591,671)			(591,671)
Stock based compensation		24,622					24,622			24,622
Disposal of noncontrolling interest of business sold								(24,039)		(24,039)
Other transactions with noncontrolling interests								580		580
Contributions from noncontrolling interests								226		226
Distributions to noncontrolling interests								(7,025)		(7,025)
BALANCE at Mar. 31, 2021	1,468	4,054,089	(895,736)	$ (7,979)	(336,852)	$ (7,979)	2,822,969	103,731	$ (7,979)	2,926,700
BALANCE at Dec. 31, 2020	1,486	4,038,149	(876,792)		(254,639)		2,908,204	111,973		3,020,177
Increase (Decrease) in Stockholders' Equity
Net income					39,359		39,359	5,919		45,278
Other comprehensive income (loss)			(18,944)				(18,944)	(15)		(18,959)
Issuance of stock	4	7,901					7,905			7,905
Repurchases of stock	(22)	(1,220)			(121,572)		(122,814)			(122,814)
Stock based compensation		9,259					9,259			9,259
Disposal of noncontrolling interest of business sold								(10,969)		(10,969)
Other transactions with noncontrolling interests								(1,727)		(1,727)
Contributions from noncontrolling interests								147		147
Distributions to noncontrolling interests								(1,597)		(1,597)
BALANCE at Mar. 31, 2021	1,468	4,054,089	(895,736)	$ (7,979)	(336,852)	$ (7,979)	2,822,969	103,731	$ (7,979)	2,926,700
BALANCE at Sep. 30, 2021	1,432	4,115,541	(900,377)		(504,126)		2,712,470	117,107		2,829,577
Increase (Decrease) in Stockholders' Equity
Net income					103,105		103,105	6,685		109,790
Other comprehensive income (loss)			36,290				36,290	8		36,298
Dividends declared					(42,951)		(42,951)			(42,951)
Issuance of stock	19	13,584					13,603			13,603
Repurchases of stock	(44)	(49,939)			(262,811)		(312,794)			(312,794)
Stock based compensation		21,719					21,719			21,719
Other transactions with noncontrolling interests								(118)		(118)
Contributions from noncontrolling interests								2		2
Distributions to noncontrolling interests								(5,473)		(5,473)
BALANCE at Mar. 31, 2022	1,407	4,100,905	(864,087)		(706,783)		2,531,442	118,211		2,649,653
BALANCE at Dec. 31, 2021	1,413	4,085,333	(899,172)		(676,902)		2,510,672	115,567		2,626,239
Increase (Decrease) in Stockholders' Equity
Net income					41,557		41,557	6,956		48,513
Other comprehensive income (loss)			35,085				35,085	128		35,213
Dividends declared					(21,445)		(21,445)			(21,445)
Issuance of stock		4,154					4,154			4,154
Repurchases of stock	(6)	(487)			(49,993)		(50,486)			(50,486)
Stock based compensation		11,905					11,905			11,905
Other transactions with noncontrolling interests								35		35
Distributions to noncontrolling interests								(4,475)		(4,475)
BALANCE at Mar. 31, 2022	$ 1,407	$ 4,100,905	$ (864,087)		$ (706,783)		$ 2,531,442	$ 118,211		$ 2,649,653