Long-Term Debt - Additional Information (Detail)				3 Months Ended			6 Months Ended
	Aug. 08, 2017 USD ($)	Mar. 30, 2017 USD ($)	Jan. 03, 2017 USD ($)	Jun. 30, 2017 USD ($) Swap	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Jun. 30, 2017 USD ($) Swap	Jun. 30, 2016 USD ($)	May 14, 2013	Dec. 01, 2009 USD ($)
Debt Instrument [Line Items]
Repayment of revolving credit facility							$ 65,000,000	$ 20,000,000
Long-term debt				$ 1,596,899,000		$ 1,598,001,000	1,596,899,000
Outstanding letters of credit				$ 19,050,000			$ 19,050,000
Cash paid for interest			$ 12,904,000
Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Number of interest rate swaps held | Swap				5			5
Notional amount of interest rate swap				$ 1,000,000,000			$ 1,000,000,000
Maturity of interest rate swap							May 14, 2020
Weighted average fixed interest rate				2.45%			2.45%
Variable rate of interest				0.75%			0.75%
Variable rate of interest, description							variable rate of interest based upon the greater of 0.75% or the three month BBA LIBOR
Senior Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Percentage of annual excess cash flow used to prepay outstanding loan							50.00%
Percentage of net proceeds from sale of non-ordinary assets				100.00%			100.00%
Percentage of net proceeds incurrence of debt							100.00%
Mandatory prepayments					$ 6,300,000
First lien secured net leverage ratio							350.00%
Percentage of interest in subsidiary				100.00%			100.00%
Line of credit facility collateral description							The Senior Secured Credit Facilities are collateralized by first priority or equivalent security interests, subject to certain exceptions, in (i) all the capital stock of, or other equity interests in, SEA and substantially all of SEA’s direct or indirect material wholly-owned domestic subsidiaries and 65% of the capital stock of, or other equity interests in, any “first tier” foreign subsidiaries and (ii) certain tangible and intangible assets of SEA and the Company.
Percentage of capital stock							65.00%
Cash paid for interest						12,904,000	$ 50,208,000	$ 28,301,000
Term B-5 Loans [Member]
Debt Instrument [Line Items]
Debt instrument, balance					$ 998,306,000
Discount initially recorded							4,992,000
Debt issuance costs initially recorded				$ 44,000			44,000
Write-off of discounts and debt issuance costs							7,987,000
Long-term debt				$ 995,810,000			$ 995,810,000
Long-term debt, maturity date							Mar. 31, 2024
Percent of original principal amount on effective date used to calculate aggregate annual amount which will amortize in equal quarterly installments					1.00%
Interest rate, description							Borrowings of Term B-5 Loans under the Senior Secured Credit Facilities bear interest, at SEA’s option, at a rate equal to an applicable margin over either (a) a base rate determined by reference to the higher of (1) the rate of interest in effect for such day as publicly announced from time to time by Bank of America, N.A. as its “prime rate” and (2) the federal funds rate plus 1/2 of 1% or (b) a LIBOR rate determined by reference to the British Bankers Association (“BBA”) LIBOR Rate, or the successor thereto if the BBA is no longer making a LIBOR rate available for the interest period relevant to such borrowing.
Debt instrument interest rate effective percentage				3.19%			3.19%
Debt instrument interest rate selected percentage				4.30%			4.30%
Term B-5 Loans [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							0.50%
Term B-5 Loans [Member] | Base Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							2.00%
Term B-5 Loans [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							3.00%
Term B-5 Loans [Member] | Minimum [Member] | Base Rate Loan [Member]
Debt Instrument [Line Items]
Debt instrument interest rate effective percentage				1.75%			1.75%
Term B-5 Loans [Member] | Minimum [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Debt instrument interest rate effective percentage				0.75%			0.75%
Term B-2 Loans [Member]
Debt Instrument [Line Items]
Debt instrument, balance										$ 1,405,000,000
Repayment of outstanding principal					$ 753,593,000
Long-term debt				$ 561,089,000		$ 1,327,850,000	$ 561,089,000
Long-term debt, maturity date							May 14, 2020
Percent of original principal amount on effective date used to calculate aggregate annual amount which will amortize in equal quarterly installments									1.00%
Interest rate, description							The Term B-2 Loans were initially borrowed in an aggregate principal amount of $1,405,000. Borrowings under the Senior Secured Credit Facilities bear interest, at SEA’s option, at a rate equal to a margin over either (a) a base rate determined by reference to the higher of (1) the rate of interest in effect for such day as publicly announced from time to time by Bank of America, N.A. as its “prime rate” and (2) the federal funds effective rate plus 1/2 of 1% or (b) a LIBOR rate based on the BBA LIBOR rate, or the successor thereto if the BBA is no longer making a LIBOR rate available, for the interest period relevant to such borrowing.
Debt instrument interest rate effective percentage				3.26%		3.26%	3.26%
Debt instrument interest rate selected percentage				3.55%			3.55%
Basis point step-down in applicable margin, description							The applicable margin for the Term B-2 Loans (under either a base rate or LIBOR rate) is subject to one 25 basis point step-down upon achievement by SEA of a total net leverage ratio equal to or less than 3.25 to 1.00.
Basis point step down on applicable margin upon achievement of certain leverage ratio							25.00%
Maximum Total Leverage Ratio							325.00%
Term B-2 Loans [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							0.50%
Term B-2 Loans [Member] | Base Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							1.25%
Term B-2 Loans [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							2.25%
Term B-2 Loans [Member] | Minimum [Member] | Base Rate Loan [Member]
Debt Instrument [Line Items]
Debt instrument interest rate effective percentage				1.75%			1.75%
Term B-2 Loans [Member] | Minimum [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Debt instrument interest rate effective percentage				0.75%			0.75%
Term B-2 Loans [Member] | Senior Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Mandatory prepayments				$ 2,800,000
Term B-3 Loans [Member]
Debt Instrument [Line Items]
Repayment of outstanding principal					244,713,000
Long-term debt						$ 245,800,000
Debt instrument interest rate effective percentage						4.33%
Mandatory Prepayment of Debt [Member]
Debt Instrument [Line Items]
Write-off of discounts and debt issuance costs		$ 33,000
Voluntary Prepayment of Debt [Member]
Debt Instrument [Line Items]
Write-off of discounts and debt issuance costs							$ 123,000
Term B-2 and Term B-3 Loans [Member] | Senior Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Mandatory prepayments					$ 3,500,000
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Long-term debt				40,000,000		$ 24,351,000	40,000,000
Senior secured revolving				210,000,000			$ 210,000,000
Debt instrument, maturity date description							The New Revolving Credit Facility will mature on the earlier of (a) March 31, 2022 and (b) the 91st day prior to the earlier of (1) the maturity of the Term B-2 Loans with an aggregate principal amount greater than $50,000 and (2) the maturity date of any indebtedness incurred to refinance the Term B-2 loans with an aggregate principal amount greater than $50,000.
Permitted increased commitments under the New Revolving Credit Facility in aggregate principal amount				$ 350,000,000			$ 350,000,000
Interest rate, description							Borrowings of loans in the New Revolving Credit Facility under the Senior Secured Credit Facilities bear interest at a rate equal to an applicable margin over either, at SEA’s option, (a) a base rate determined by reference to the higher of (1) the federal funds rate plus 1/2 of 1%, and (2) the rate of interest in effect for such day as publicly announced from time to time by Bank of America, N.A. as its “prime rate”, in each case, plus an applicable margin equal to 1.75% or (b) a LIBOR rate or the successor thereto if the BBA is no longer making a LIBOR rate available, for the interest period relevant to such borrowing (provided in no event shall such LIBOR rate with respect to the borrowings be less than 0.0% per annum).
Debt instrument interest rate selected percentage				3.94%			3.94%
Basis point step-down in applicable margin, description							The applicable margin for borrowings under the New Revolving Credit Facility is 1.75%, in the case of base rate loans, and 2.75%, in the case of LIBOR rate loans. The applicable margin for borrowings under the New Revolving Credit Facility are subject to one 25 basis point step-down upon achievement by SEA of certain corporate credit ratings, which the Company did not achieve as of June 30, 2017.
Basis point step down on applicable margin upon achievement of certain leverage ratio							25.00%
Commitment fees on unused portion of facility							0.50%
Amount available for borrowing				$ 150,950,000			$ 150,950,000
Revolving Credit Facility [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							0.50%
Revolving Credit Facility [Member] | Base Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							1.75%
Revolving Credit Facility [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans							2.75%
Revolving Credit Facility [Member] | Minimum [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Debt instrument interest rate effective percentage				0.00%			0.00%
Revolving Credit Facility [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayment of revolving credit facility	$ 40,000,000
Restrictive Covenants [Member]
Debt Instrument [Line Items]
Restrictive covenants, restricted payments capacity available							$ 90,000,000
Maximum total net leverage ratio							5.75%
Restrictive Covenants [Member] | Senior Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Restrictive covenants, description							The Senior Secured Credit Facilities permit restricted payments in an aggregate amount per annum equal to the sum of (A) $25,000 plus (B) an amount, if any, equal to (1) if the total net leverage ratio on a pro forma basis after giving effect to the payment of any such restricted payment, is no greater than 3.50 to 1.00, an unlimited amount, (2) if the total net leverage ratio on a pro forma basis after giving effect to the payment of any such restricted payment is no greater than 4.00 to 1.00 and greater than 3.50 to 1.00, the greater of (a) $95,000 and (b) 7.50% of market capitalization (as defined in the Senior Secured Credit Facilities), (3) if the total net leverage ratio on a pro forma basis after giving effect to the payment of any such restricted payment is no greater than 4.50 to 1.00 and greater than 4.00 to 1.00, $95,000 and (4) if the total net leverage ratio on a pro forma basis after giving effect to the payment of any such restricted payment is no greater than 5.00 to 1.00 and greater than 4.50 to 1.00, $65,000.
Percentage of Market Capitalization on restricted payment							7.50%
First lien secured net leverage ratio							350.00%
Total net leverage ratio, as calculated							4.77%
Restrictive Covenants [Member] | Senior Secured Credit Facilities [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of annual excess cash flow used to prepay outstanding loan							25.00%
Restricted payment on Senior Secured Credit Facilities, base payment							$ 25,000,000
Restricted payment on Senior Secured Credit Facilities, first payment							95,000,000
Restricted payment on Senior Secured Credit Facilities, second payment							95,000,000
Restricted payment on Senior Secured Credit Facilities, third payment							$ 65,000,000
Total net leverage ratio, one							400.00%
Total net leverage ratio, two							450.00%
Total net leverage ratio, three							500.00%
Restrictive Covenants [Member] | Senior Secured Credit Facilities [Member] | Minimum [Member]
Debt Instrument [Line Items]
Percentage of annual excess cash flow used to prepay outstanding loan							0.00%
Total net leverage ratio, one							350.00%
Total net leverage ratio, two							400.00%
Total net leverage ratio, three							450.00%