Long-Term Debt - Additional Information (Detail)		3 Months Ended		6 Months Ended
	Apr. 07, 2015 USD ($)	Jun. 30, 2015 USD ($) Swap	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Swap	Jun. 30, 2014 USD ($)	Jun. 10, 2015 USD ($)	Apr. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	May. 14, 2013	Dec. 01, 2009 USD ($)
Debt Instrument [Line Items]
Unamortized discount		$ 8,213,000		$ 8,213,000				$ 8,985,000
Long-term debt		1,624,713,000		1,624,713,000				1,612,438,000
Mandatory prepayments		0	$ 0	0	$ 0
Outstanding letters of credit		18,000,000		18,000,000
Letters of credit available amount		174,500,000		$ 174,500,000
Commitment fees on unused portion of facility				0.50%
Restrictive covenants, description				The Senior Secured Credit Facilities permit restricted payments in an aggregate amount per annum not to exceed the greater of (1) 6% of initial public offering net proceeds received by SEA or (2) (a) $90,000, so long as, on a Pro Forma Basis (as defined in the Senior Secured Credit Facilities) after giving effect to the payment of any such restricted payment, the Total Leverage Ratio, (as defined in the Senior Secured Credit Facilities), is no greater than 5.00 to 1.00 and greater than 4.50 to 1.00, (b) $120,000, so long as, on a Pro Forma Basis after giving effect to the payment of any such restricted payment, the Total Leverage Ratio is no greater than 4.50 to 1.00 and greater than 4.00 to 1.00, (c) the greater of (A) $120,000 and (B) 7.5% of Market Capitalization (as defined in the Senior Secured Credit Facilities), so long as, on a Pro Forma Basis after giving effect to the payment of any such restricted payment, the Total Leverage Ratio is no greater than 4.00 to 1.00 and greater than 3.50 to 1.00 and (d) an unlimited amount, so long as, on a Pro Forma Basis after giving effect to the payment of any such restricted payment, the Total Leverage Ratio is no greater than 3.50 to 1.00.
Percentage of initial public offering net proceeds in restricted payments				6.00%
Percentage of Market Capitalization on restricted payment				7.50%
Restrictive covenants, restricted payments used				$ 54,500,000
Restrictive covenants, restricted payments capacity remaining				65,500,000
Cash paid for interest				$ 35,201,000	$ 37,355,000
Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, balance										$ 400,000,000
Long-term debt, maturity date				Dec. 01, 2016
Redemption price for Senior Notes Percentage	105.50%
Debt redemption premium	$ 14,300,000
Write-off discounts and debt issuance costs	6,048,000
Long-term debt								260,000,000
Term B-3 Loans [Member]
Debt Instrument [Line Items]
Debt instrument, balance	280,000,000
Long-term debt, maturity date				May 14, 2020
Repayment of Senior Notes outstanding principal amount	$ 260,000,000
Unamortized discount		1,400,000		$ 1,400,000
Debt issuance costs		3,171,000
Long-term debt		$ 279,300,000		$ 279,300,000
Interest rate, description				Borrowings of Term B-3 Loans bear interest at a fluctuating rate per annum equal to, at SEA's option, (i) a base rate equal to the higher of (a) the federal funds rate plus 1/2 of 1% and (b) 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" or (ii) a LIBOR rate determined by reference to 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 selected percentage		4.00%		4.00%
Percent of original principal amount on effective date used to calculate aggregate annual amount which will amortize in equal quarterly installments	1.00%
Term B-2 Loans [Member]
Debt Instrument [Line Items]
Debt instrument, balance										$ 1,405,000,000
Long-term debt, maturity date				May 14, 2020
Long-term debt		$ 1,345,413,000		$ 1,345,413,000				$ 1,352,438,000
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 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.
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 certain total net leverage ratio.
Basis point step down on applicable margin upon achievement of certain leverage ratio				0.25%
Debt instrument interest rate selected percentage		3.00%		3.00%
Percent of original principal amount on effective date used to calculate aggregate annual amount which will amortize in equal quarterly installments									1.00%
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%
First lien secured net leverage ratio				3.50%
Federal Funds Rate [Member] | Term B-3 Loans [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans	0.50%
Federal Funds Rate [Member] | Term B-2 Loans [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans				0.50%
Base Rate Loan [Member] | Term B-3 Loans [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans	2.25%
Floor rate	1.75%
Base Rate Loan [Member] | Term B-2 Loans [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans				1.25%
Floor rate				1.75%
LIBOR Rate Loan [Member] | Term B-3 Loans [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans	3.25%
Floor rate	0.75%
LIBOR Rate Loan [Member] | Term B-2 Loans [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans				2.25%
Floor rate				0.75%
Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Maturity of interest rate swap				Sep. 30, 2016
Variable rate of interest		0.75%		0.75%
Interest Rate Swaps [Member] | Term B-3 Loans [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap							$ 250,000,000
Maturity of interest rate swap				Sep. 30, 2016
Variable rate of interest		0.75%		0.75%
Fixed rate of interest on swaps		0.901%		0.901%
Interest Rate Swaps [Member] | Combined Interest Rate Cash Flow Hedges On Three Swaps [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap		$ 1,000,000,000		$ 1,000,000,000
Number of interest rate swap held | Swap		4		4
Number of interest rate derivatives held with combined notional amount | Swap		3		3
Interest Rate Swaps [Member] | Combined Interest Rate Cash Flow Hedges On Three Swaps [Member] | Maximum [Member]
Debt Instrument [Line Items]
Fixed rate of interest on swaps		1.051%		1.051%
Interest Rate Swaps [Member] | Combined Interest Rate Cash Flow Hedges On Three Swaps [Member] | Minimum [Member]
Debt Instrument [Line Items]
Fixed rate of interest on swaps		1.049%		1.049%
Forward Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap						$ 1,000,000,000
Maturity of interest rate swap				May 14, 2020
Variable rate of interest						0.75%
Weighted average fixed interest rate						2.45%
Subject to SEA Attaining Certain Total Leverage Ratios [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%
Subject to SEA Attaining Certain Total Leverage Ratios [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%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Senior secured revolving		$ 192,500,000		$ 192,500,000
Interest rate, description				Borrowings of loans under the Revolving Credit Facility bear interest at a fluctuating rate per annum equal to, at SEA's option, a base rate equal to the higher of (a) the federal funds rate plus 1/2 of 1%, and (b) 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".
Basis point step-down in applicable margin, description				The applicable margin for borrowings under the 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 (under either a base rate or LIBOR rate) is subject to one 25 basis point step-down upon achievement by SEA of certain corporate credit ratings.
Basis point step down on applicable margin upon achievement of certain leverage ratio				0.25%
Debt instrument interest rate selected percentage		2.50%		2.50%
Permitted increased commitments under the Revolving Credit Facility in aggregate principal amount		$ 350,000,000		$ 350,000,000
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%
Restrictive Covenants [Member]
Debt Instrument [Line Items]
Restrictive covenants, restricted payments capacity available				$ 120,000,000
Restrictive Covenants [Member] | Senior Secured Credit Facilities [Member]
Debt Instrument [Line Items]
Total Leverage Ratio				4.42%
Restrictive Covenants [Member] | Subject to SEA Attaining Certain Total Leverage Ratios [Member]
Debt Instrument [Line Items]
Restricted payment on Senior Secured Credit Facilities				$ 90,000,000
Maximum Total Leverage Ratio				5.00%
Minimum Total Leverage Ratio				4.50%
Restrictive Covenants [Member] | Scenario Two [Member]
Debt Instrument [Line Items]
Restricted payment on Senior Secured Credit Facilities				$ 120,000,000
Maximum Total Leverage Ratio				4.50%
Minimum Total Leverage Ratio				4.00%
Restrictive Covenants [Member] | Scenario Three [Member]
Debt Instrument [Line Items]
Restricted payment on Senior Secured Credit Facilities				$ 120,000,000
Maximum Total Leverage Ratio				4.00%
Minimum Total Leverage Ratio				3.50%