Consolidating Financial Information of Guarantors and Issuers Income Statement (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 25, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Condensed Financial Statements, Captions [Line Items]
Net revenues		$ 1,348,530	$ 1,321,967	$ 1,288,721
Costs and expenses:
Cost of food, merchandise and games revenues		114,733	110,811	106,608
Operating expenses		584,350	558,102	538,881
Selling, general and administrative		193,333	193,770	181,830
Depreciation and amortization		155,529	153,222	131,876
Loss on impairment / retirement of fixed assets, net		10,178	12,728	12,587
Gain on sale of investment		(112)	(1,877)	0
Total costs and expenses		1,058,011	1,026,756	971,782
Operating income		290,519	295,211	316,939
Interest expense (income), net		84,172	84,748	83,686
Net effect of swaps		7,442	(45)	(1,197)
Loss on early debt extinguishment	$ 1,100	1,073	23,121	0
(Gain) loss on foreign currency		36,254	(29,086)	(14,656)
Other (income) expense		182	(115)	0
(Income) loss from investment in affiliates		0	0	0
Income before taxes		161,396	216,588	249,106
Provision for taxes		34,743	1,112	71,418
Net income		126,653	215,476	177,688
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		17,240	(14,849)	(3,700)
Cash flow hedging derivative activity		8,366	7,975	3,350
Net other comprehensive income (loss)		25,606	(6,874)	(350)
Total comprehensive income		152,259	208,602	177,338
June 2014 Notes [Member] | Reportable Legal Entities [Member] | Cedar Fair L.P. (Parent) [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		103,687	104,080	144,042
Costs and expenses:
Cost of food, merchandise and games revenues		0	0	0
Operating expenses		0	0	0
Selling, general and administrative		2,301	3,007	3,029
Depreciation and amortization		0	0	0
Loss on impairment / retirement of fixed assets, net		0	0	0
Gain on sale of investment		0	0
Total costs and expenses		2,301	3,007	3,029
Operating income		101,386	101,073	141,013
Interest expense (income), net		23,339	23,739	32,643
Net effect of swaps		1,228	(150)	(473)
Loss on early debt extinguishment		0	11,773
(Gain) loss on foreign currency		0	0	0
Other (income) expense		250	250	250
(Income) loss from investment in affiliates		(61,484)	(160,925)	(80,295)
Income before taxes		138,053	226,386	188,888
Provision for taxes		11,400	10,910	11,200
Net income		126,653	215,476	177,688
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		17,240	(14,849)	(3,700)
Cash flow hedging derivative activity		8,366	7,975	3,350
Net other comprehensive income (loss)		25,606	(6,874)	(350)
Total comprehensive income		152,259	208,602	177,338
June 2014 Notes [Member] | Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		1,268,200	1,239,067	1,234,075
Costs and expenses:
Cost of food, merchandise and games revenues		103,892	99,328	96,740
Operating expenses		692,731	666,063	720,390
Selling, general and administrative		112,864	112,394	100,228
Depreciation and amortization		140,223	137,535	117,025
Loss on impairment / retirement of fixed assets, net		9,957	12,072	12,428
Gain on sale of investment		0	0
Total costs and expenses		1,059,667	1,027,392	1,046,811
Operating income		208,533	211,675	187,264
Interest expense (income), net		18,514	17,333	1,526
Net effect of swaps		0	0	0
Loss on early debt extinguishment		886	2,955
(Gain) loss on foreign currency		0	0	4
Other (income) expense		74,307	69,756	79,482
(Income) loss from investment in affiliates		2,517	(84,398)	(27,628)
Income before taxes		112,309	206,029	133,880
Provision for taxes		25,735	(8,724)	40,201
Net income		86,574	214,753	93,679
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		0	0	0
Cash flow hedging derivative activity		0	0	0
Net other comprehensive income (loss)		0	0	0
Total comprehensive income		86,574	214,753	93,679
June 2014 Notes [Member] | Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		(484,641)	(466,605)	(528,303)
Costs and expenses:
Cost of food, merchandise and games revenues		0	0	0
Operating expenses		(484,641)	(466,605)	(528,303)
Selling, general and administrative		0	0	0
Depreciation and amortization		0	0	0
Loss on impairment / retirement of fixed assets, net		0	0	0
Gain on sale of investment		0	0
Total costs and expenses		(484,641)	(466,605)	(528,303)
Operating income		0	0	0
Interest expense (income), net		0	0	0
Net effect of swaps		0	0	0
Loss on early debt extinguishment		0	0
(Gain) loss on foreign currency		0	0	0
Other (income) expense		0	0	0
(Income) loss from investment in affiliates		145,540	460,078	201,600
Income before taxes		(145,540)	(460,078)	(201,600)
Provision for taxes		0	0	0
Net income		(145,540)	(460,078)	(201,600)
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		(17,240)	14,849	3,700
Cash flow hedging derivative activity		(2,813)	(2,422)	(1,060)
Net other comprehensive income (loss)		(20,053)	12,427	2,640
Total comprehensive income		(165,593)	(447,651)	(198,960)
April 2017 notes | Reportable Legal Entities [Member] | Cedar Fair L.P. (Parent) [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		103,687	104,080	144,042
Costs and expenses:
Cost of food, merchandise and games revenues		0	0	0
Operating expenses		0	0	0
Selling, general and administrative		2,301	3,007	3,029
Depreciation and amortization		0	0	0
Loss on impairment / retirement of fixed assets, net		0	0	0
Gain on sale of investment		0	0
Total costs and expenses		2,301	3,007	3,029
Operating income		101,386	101,073	141,013
Interest expense (income), net		23,339	23,739	32,643
Net effect of swaps		1,228	(150)	(473)
Loss on early debt extinguishment		0	11,773
(Gain) loss on foreign currency		0	0	0
Other (income) expense		250	250	250
(Income) loss from investment in affiliates		(61,484)	(160,925)	(80,295)
Income before taxes		138,053	226,386	188,888
Provision for taxes		11,400	10,910	11,200
Net income		126,653	215,476	177,688
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		17,240	(14,849)	(3,700)
Cash flow hedging derivative activity		8,366	7,975	3,350
Net other comprehensive income (loss)		25,606	(6,874)	(350)
Total comprehensive income		152,259	208,602	177,338
April 2017 notes | Reportable Legal Entities [Member] | Guarantor Subsidiaries [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		382,569	395,745	378,556
Costs and expenses:
Cost of food, merchandise and games revenues		18,194	18,386	17,756
Operating expenses		42,860	44,130	49,393
Selling, general and administrative		19,130	19,867	15,058
Depreciation and amortization		140,223	137,535	117,025
Loss on impairment / retirement of fixed assets, net		7,697	8,970	9,742
Gain on sale of investment		0	0
Total costs and expenses		228,104	228,888	208,974
Operating income		154,465	166,857	169,582
Interest expense (income), net		(33,129)	(22,435)	(14,169)
Net effect of swaps		0	0	0
Loss on early debt extinguishment		0	0
(Gain) loss on foreign currency		0	0	0
Other (income) expense		74,307	69,756	79,482
(Income) loss from investment in affiliates		2,517	(84,398)	(27,628)
Income before taxes		110,770	203,934	131,897
Provision for taxes		24,196	(10,819)	38,218
Net income		86,574	214,753	93,679
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		0	0	0
Cash flow hedging derivative activity		0	0	0
Net other comprehensive income (loss)		0	0	0
Total comprehensive income		86,574	214,753	93,679
April 2017 notes | Eliminations [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		(594,360)	(583,391)	(635,147)
Costs and expenses:
Cost of food, merchandise and games revenues		0	0	0
Operating expenses		(594,360)	(583,391)	(635,147)
Selling, general and administrative		0	0	0
Depreciation and amortization		0	0	0
Loss on impairment / retirement of fixed assets, net		0	0	0
Gain on sale of investment		0	0
Total costs and expenses		(594,360)	(583,391)	(635,147)
Operating income		0	0	0
Interest expense (income), net		0	0	0
Net effect of swaps		0	0	0
Loss on early debt extinguishment		0	0
(Gain) loss on foreign currency		0	0	0
Other (income) expense		0	0	0
(Income) loss from investment in affiliates		145,540	460,078	201,600
Income before taxes		(145,540)	(460,078)	(201,600)
Provision for taxes		0	0	0
Net income		(145,540)	(460,078)	(201,600)
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		(17,240)	14,849	3,700
Cash flow hedging derivative activity		(2,813)	(2,422)	(1,060)
Net other comprehensive income (loss)		(20,053)	12,427	2,640
Total comprehensive income		(165,593)	(447,651)	(198,960)
Co-Issuer Subsidiary (Magnum) [Member] | June 2014 Notes [Member] | Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		336,778	317,496	320,945
Costs and expenses:
Cost of food, merchandise and games revenues		0	0	0
Operating expenses		328,709	313,654	303,974
Selling, general and administrative		67,582	67,872	68,422
Depreciation and amortization		33	33	35
Loss on impairment / retirement of fixed assets, net		0	0	0
Gain on sale of investment		(112)	(1,877)
Total costs and expenses		396,212	379,682	372,431
Operating income		(59,434)	(62,186)	(51,486)
Interest expense (income), net		18,331	18,837	24,114
Net effect of swaps		6,214	105	(724)
Loss on early debt extinguishment		187	8,188
(Gain) loss on foreign currency		51	(25)	0
Other (income) expense		(78,571)	(73,581)	(83,657)
(Income) loss from investment in affiliates		(62,244)	(176,698)	(73,132)
Income before taxes		56,598	160,988	81,913
Provision for taxes		(4,886)	60	1,621
Net income		61,484	160,928	80,292
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		0	0	0
Cash flow hedging derivative activity		2,813	2,422	1,060
Net other comprehensive income (loss)		2,813	2,422	1,060
Total comprehensive income		64,297	163,350	81,352
Co-Issuer Subsidiary (Magnum) [Member] | April 2017 notes | Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		336,778	317,496	320,945
Costs and expenses:
Cost of food, merchandise and games revenues		0	0	0
Operating expenses		328,709	313,654	303,974
Selling, general and administrative		67,582	67,872	68,422
Depreciation and amortization		33	33	35
Loss on impairment / retirement of fixed assets, net		0	0	0
Gain on sale of investment		(112)	(1,877)
Total costs and expenses		396,212	379,682	372,431
Operating income		(59,434)	(62,186)	(51,486)
Interest expense (income), net		18,331	18,837	24,114
Net effect of swaps		6,214	105	(724)
Loss on early debt extinguishment		187	8,188
(Gain) loss on foreign currency		51	(25)	0
Other (income) expense		(78,571)	(73,581)	(83,657)
(Income) loss from investment in affiliates		(62,244)	(176,698)	(73,132)
Income before taxes		56,598	160,988	81,913
Provision for taxes		(4,886)	60	1,621
Net income		61,484	160,928	80,292
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		0	0	0
Cash flow hedging derivative activity		2,813	2,422	1,060
Net other comprehensive income (loss)		2,813	2,422	1,060
Total comprehensive income		64,297	163,350	81,352
Co-Issuer Subsidiary (Cedar Canada) [Member] | June 2014 Notes [Member] | Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		124,506	127,929	117,962
Costs and expenses:
Cost of food, merchandise and games revenues		10,841	11,483	9,868
Operating expenses		47,551	44,990	42,820
Selling, general and administrative		10,586	10,497	10,151
Depreciation and amortization		15,273	15,654	14,816
Loss on impairment / retirement of fixed assets, net		221	656	159
Gain on sale of investment		0	0
Total costs and expenses		84,472	83,280	77,814
Operating income		40,034	44,649	40,148
Interest expense (income), net		23,988	24,839	25,403
Net effect of swaps		0	0	0
Loss on early debt extinguishment		0	205
(Gain) loss on foreign currency		36,203	(29,061)	(14,660)
Other (income) expense		4,196	3,460	3,925
(Income) loss from investment in affiliates		(24,329)	(38,057)	(20,545)
Income before taxes		(24)	83,263	46,025
Provision for taxes		2,494	(1,134)	18,396
Net income		(2,518)	84,397	27,629
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		17,240	(14,849)	(3,700)
Cash flow hedging derivative activity		0	0	0
Net other comprehensive income (loss)		17,240	(14,849)	(3,700)
Total comprehensive income		14,722	69,548	23,929
Co-Issuer Subsidiary (Cedar Canada) [Member] | April 2017 notes | Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		124,506	127,929	117,962
Costs and expenses:
Cost of food, merchandise and games revenues		10,841	11,483	9,868
Operating expenses		47,551	44,990	42,820
Selling, general and administrative		10,586	10,497	10,151
Depreciation and amortization		15,273	15,654	14,816
Loss on impairment / retirement of fixed assets, net		221	656	159
Gain on sale of investment		0	0
Total costs and expenses		84,472	83,280	77,814
Operating income		40,034	44,649	40,148
Interest expense (income), net		23,988	24,839	25,403
Net effect of swaps		0	0	0
Loss on early debt extinguishment		0	205
(Gain) loss on foreign currency		36,203	(29,061)	(14,660)
Other (income) expense		4,196	3,460	3,925
(Income) loss from investment in affiliates		(24,329)	(38,057)	(20,545)
Income before taxes		(24)	83,263	46,025
Provision for taxes		2,494	(1,134)	18,396
Net income		(2,518)	84,397	27,629
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		17,240	(14,849)	(3,700)
Cash flow hedging derivative activity		0	0	0
Net other comprehensive income (loss)		17,240	(14,849)	(3,700)
Total comprehensive income		14,722	69,548	23,929
Co-Issuer Subsidiary (Millennium) [Member] | April 2017 notes | Reportable Legal Entities [Member] | Subsidiary Issuer [Member]
Condensed Financial Statements, Captions [Line Items]
Net revenues		995,350	960,108	962,363
Costs and expenses:
Cost of food, merchandise and games revenues		85,698	80,942	78,984
Operating expenses		759,590	738,719	777,841
Selling, general and administrative		93,734	92,527	85,170
Depreciation and amortization		0	0	0
Loss on impairment / retirement of fixed assets, net		2,260	3,102	2,686
Gain on sale of investment		0	0
Total costs and expenses		941,282	915,290	944,681
Operating income		54,068	44,818	17,682
Interest expense (income), net		51,643	39,768	15,695
Net effect of swaps		0	0	0
Loss on early debt extinguishment		886	2,955
(Gain) loss on foreign currency		0	0	4
Other (income) expense		0	0	0
(Income) loss from investment in affiliates		0	0	0
Income before taxes		1,539	2,095	1,983
Provision for taxes		1,539	2,095	1,983
Net income		0	0	0
Other comprehensive income (loss), (net of tax):
Foreign currency translation adjustment		0	0	0
Cash flow hedging derivative activity		0	0	0
Net other comprehensive income (loss)		0	0	0
Total comprehensive income		$ 0	$ 0	$ 0