Condensed Consolidating Financial Information - Cash Flows (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities	$ 59,162	$ 69,854
Cash flows from investing activities:
Purchases of investments		(4,221)
Sales and maturities of investments	1,835	1,134
Cash paid for acquisition of businesses, net of cash acquired		(2,929)
Capital expenditures	(59,430)	(141,070)
Proceeds from sales of assets and insurance claims	6,822	2,642
Net cash (used for) provided by investing activities	(50,773)	(144,444)
Cash flows from financing activities:
Increase (decrease) in cash overdrafts	55
Proceeds from issuance of long-term debt	1,000,000
Reduction of long-term debt	(1,068,405)	(43,540)
Debt issuance costs	(15,737)	(35)
Proceeds from revolving credit facilities	795,000	180,000
Reduction in revolving credit facilities	(650,000)	(50,000)
Proceeds from (payments for) short-term borrowings		289
Dividends to common and preferred shareholders	(7,937)	(25,765)
Other changes	(1,546)	(1,493)
Repurchase of common and preferred shares	(13,858)
Net cash (used for) provided by financing activities	37,572	59,456
Effect of exchange rate changes on cash and cash equivalents	(2,219)	(2,791)
Net increase (decrease) in cash, cash equivalents and restricted cash	43,742	(17,925)
Cash and cash equivalents and restricted cash, beginning of period	442,038	451,080
Cash and cash equivalents and restricted cash, end of period	485,780	433,155
Consolidating Adjustments
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities	(4,845)	(58,468)
Cash flows from investing activities:
Cash paid for investments in consolidated affiliates	1,058,797	4,000
Net cash (used for) provided by investing activities	1,058,797	4,000
Cash flows from financing activities:
Dividends to common and preferred shareholders	545	3,168
Proceeds from parent contributions	(1,058,797)	(4,000)
Distribution from subsidiary to parent	4,300	55,300
Net cash (used for) provided by financing activities	(1,053,952)	54,468
Parent Company | Reportable Legal Entities
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities	10,163	55,162
Cash flows from investing activities:
Cash paid for investments in consolidated affiliates	(977,000)
Net cash (used for) provided by investing activities	(977,000)
Cash flows from financing activities:
Proceeds from issuance of long-term debt	1,000,000
Debt issuance costs	(15,737)
Proceeds from issuance of common shares, net of issuance costs		6
Dividends to common and preferred shareholders	(8,209)	(28,557)
Proceeds from issuance of intercompany debt	18,200	25,000
Paydown of intercompany debt	(13,200)	(50,500)
Other changes	(1,549)	(1,251)
Repurchase of common and preferred shares	(12,127)
Net cash (used for) provided by financing activities	967,378	(55,302)
Net increase (decrease) in cash, cash equivalents and restricted cash	541	(140)
Cash and cash equivalents and restricted cash, beginning of period	319	474
Cash and cash equivalents and restricted cash, end of period	860	334
Guarantor Subsidiaries | Reportable Legal Entities
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities	(71,734)	(88,799)
Cash flows from investing activities:
Change in intercompany balances	913,387	(1,627)
Net cash (used for) provided by investing activities	913,387	(1,627)
Cash flows from financing activities:
Reduction of long-term debt	(1,068,405)	(43,540)
Debt issuance costs		(35)
Proceeds from revolving credit facilities	795,000	180,000
Reduction in revolving credit facilities	(650,000)	(50,000)
Proceeds from parent contributions	81,797	4,000
Net cash (used for) provided by financing activities	(841,608)	90,425
Net increase (decrease) in cash, cash equivalents and restricted cash	45	(1)
Cash and cash equivalents and restricted cash, beginning of period	38	42
Cash and cash equivalents and restricted cash, end of period	83	41
Other Subsidiaries (Non-Guarantors) | Reportable Legal Entities
Condensed Consolidating Statements Of Cash Flows
Net cash provided by (used for) operating activities	125,578	161,959
Cash flows from investing activities:
Purchases of investments		(4,221)
Sales and maturities of investments	1,835	1,134
Cash paid for acquisition of businesses, net of cash acquired		(2,929)
Cash paid for investments in consolidated affiliates	(81,797)	(4,000)
Capital expenditures	(59,430)	(141,070)
Proceeds from sales of assets and insurance claims	6,822	2,642
Change in intercompany balances	(913,387)	1,627
Net cash (used for) provided by investing activities	(1,045,957)	(146,817)
Cash flows from financing activities:
Increase (decrease) in cash overdrafts	55
Proceeds from (payments for) short-term borrowings		289
Proceeds from issuance of common shares, net of issuance costs		(6)
Dividends to common and preferred shareholders	(273)	(376)
Proceeds from issuance of intercompany debt	(18,200)	(25,000)
Paydown of intercompany debt	13,200	50,500
Proceeds from parent contributions	977,000
Distribution from subsidiary to parent	(4,300)	(55,300)
Other changes	3	(242)
Repurchase of common and preferred shares	(1,731)
Net cash (used for) provided by financing activities	965,754	(30,135)
Effect of exchange rate changes on cash and cash equivalents	(2,219)	(2,791)
Net increase (decrease) in cash, cash equivalents and restricted cash	43,156	(17,784)
Cash and cash equivalents and restricted cash, beginning of period	441,681	450,564
Cash and cash equivalents and restricted cash, end of period	$ 484,837	$ 432,780