Condensed Consolidating Financial Information - Cash Flows (Details) - USD ($) $ in Thousands				1 Months Ended	9 Months Ended
	Oct. 02, 2018	Jul. 03, 2018	Apr. 03, 2018	Jun. 30, 2018	Sep. 30, 2018	Sep. 30, 2017
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities					$ 76,919	$ (36,109)
Cash flows from investing activities:
Purchases of investments					(676)	(6,722)
Sales and maturities of investments					2,962	12,533
Cash paid for acquisitions of businesses, net of cash acquired						(50,764)
Capital expenditures					(338,968)	(448,864)
Proceeds from sales of assets and insurance claims					86,666	32,805
Net cash (used for) provided by investing activities					(250,016)	(461,012)
Cash flows from financing activities:
Increase (decrease) in cash overdrafts					(261)	(78)
Debt issuance costs					(13,262)	(11,039)
Proceeds from (payments for) issuance of common shares				$ 21,800	301,835	8,300
Reduction of long-term debt					(774,802)	(382,815)
Dividends to shareholders	$ (21,400)	$ (21,500)	$ (19,100)		(57,661)	(51,346)
Proceeds from (payments for) commercial paper, net					(40,000)	78,000
Purchase of capped call hedge transactions						(40,250)
Proceeds from revolving credit facilities					905,000	410,000
Reduction in revolving credit facilities					(1,200,000)
Dividends to preferred shareholders					(3,680)
Proceeds from (payments for) short-term borrowings					252	(528)
Proceeds from issuance of preferred stock, net of issuance costs					278,358
Proceeds from issuance of long-term debt					800,000	411,200
Payments on term loan						(162,500)
Cash proceeds (payments) from equity component of exchangeable debt						159,952
Noncontrolling interest contribution						20,000
Distributions to noncontrolling interest					(4,676)	(7,272)
Other changes					(3,722)	(7,864)
Net cash (used for) provided by financing activities					187,381	423,760
Effect of exchange rate changes on cash and cash equivalents					(5,320)	251
Net increase (decrease) in cash and cash equivalents					8,964	(73,110)
Cash and cash equivalents and restricted cash, beginning of period					342,029	264,990
Cash and cash equivalents and restricted cash, end of period					350,993	191,880
Consolidating Adjustments
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities					(40,017)	(88,939)
Cash flows from investing activities:
Cash paid for investments in consolidated affiliates					786,500	76,060
Net cash (used for) provided by investing activities					786,500	76,060
Cash flows from financing activities:
Dividends to shareholders					9,317	8,939
Proceeds from parent contributions					(786,500)	(76,060)
Distribution from subsidiary to parent					30,700	80,000
Net cash (used for) provided by financing activities					(746,483)	12,879
Parent Company | Reportable Legal Entities
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities					82,365	103,187
Cash flows from investing activities:
Cash paid for investments in consolidated affiliates					(587,500)	(100)
Net cash (used for) provided by investing activities					(587,500)	(100)
Cash flows from financing activities:
Proceeds from (payments for) issuance of common shares					301,835	8,300
Dividends to shareholders					(66,978)	(60,285)
Proceeds from issuance of intercompany debt					20,000	35,000
Dividends to preferred shareholders					(3,680)
Proceeds from issuance of preferred stock, net of issuance costs					278,358
Paydown of intercompany debt					(21,000)	(79,000)
Other changes					(3,722)	(7,864)
Net cash (used for) provided by financing activities					504,813	(103,849)
Net increase (decrease) in cash and cash equivalents					(322)	(762)
Cash and cash equivalents and restricted cash, beginning of period					1,091	1,148
Cash and cash equivalents and restricted cash, end of period					769	386
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities					(203,493)	(199,071)
Cash flows from investing activities:
Change in intercompany balances					327,555	(424,133)
Net cash (used for) provided by investing activities					327,555	(424,133)
Cash flows from financing activities:
Debt issuance costs					(13,262)	(11,039)
Reduction of long-term debt					(774,802)	(270,269)
Proceeds from (payments for) commercial paper, net					(40,000)	78,000
Proceeds from issuance of intercompany debt						20,000
Purchase of capped call hedge transactions						(40,250)
Proceeds from revolving credit facilities					905,000	410,000
Reduction in revolving credit facilities					(1,200,000)
Proceeds from issuance of long-term debt					800,000	411,200
Payments on term loan						(162,500)
Paydown of intercompany debt						(20,000)
Cash proceeds (payments) from equity component of exchangeable debt						159,952
Proceeds from parent contributions					199,000	37,980
Net cash (used for) provided by financing activities					(124,064)	613,074
Net increase (decrease) in cash and cash equivalents					(2)	(10,130)
Cash and cash equivalents and restricted cash, beginning of period					44	10,177
Cash and cash equivalents and restricted cash, end of period					42	47
Other Subsidiaries (Non-Guarantors) | Reportable Legal Entities
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities					238,064	148,714
Cash flows from investing activities:
Purchases of investments					(676)	(6,722)
Sales and maturities of investments					2,962	12,533
Cash paid for acquisitions of businesses, net of cash acquired						(50,764)
Cash paid for investments in consolidated affiliates					(199,000)	(75,960)
Capital expenditures					(338,968)	(448,864)
Proceeds from sales of assets and insurance claims					86,666	32,805
Change in intercompany balances					(327,555)	424,133
Net cash (used for) provided by investing activities					(776,571)	(112,839)
Cash flows from financing activities:
Increase (decrease) in cash overdrafts					(261)	(78)
Reduction of long-term debt						(112,546)
Proceeds from issuance of intercompany debt					(20,000)	(55,000)
Proceeds from (payments for) short-term borrowings					252	(528)
Paydown of intercompany debt					21,000	99,000
Noncontrolling interest contribution						20,000
Distributions to noncontrolling interest					(4,676)	(7,272)
Proceeds from parent contributions					587,500	38,080
Distribution from subsidiary to parent					(30,700)	(80,000)
Net cash (used for) provided by financing activities					553,115	(98,344)
Effect of exchange rate changes on cash and cash equivalents					(5,320)	251
Net increase (decrease) in cash and cash equivalents					9,288	(62,218)
Cash and cash equivalents and restricted cash, beginning of period					340,894	253,665
Cash and cash equivalents and restricted cash, end of period					$ 350,182	$ 191,447