Long-Term Debt - Additional Information (Detail)			1 Months Ended	3 Months Ended		9 Months Ended
	Sep. 30, 2015 USD ($) Swap	Apr. 07, 2015 USD ($)	Oct. 31, 2015 USD ($)	Sep. 30, 2015 USD ($) Swap	Sep. 30, 2014 USD ($)	Sep. 30, 2015 USD ($) Swap	Sep. 30, 2014 USD ($)	Jun. 10, 2015 USD ($) Swap	Apr. 30, 2015 USD ($)	Dec. 31, 2014 USD ($)	May. 14, 2013	Dec. 01, 2009 USD ($)
Debt Instrument [Line Items]
Long-term debt	$ 1,620,500,000			$ 1,620,500,000		$ 1,620,500,000				$ 1,612,438,000
Outstanding letters of credit	$ 18,000,000			$ 18,000,000		$ 18,000,000
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						$ 87,700,000
Restrictive covenants, restricted payments capacity remaining						32,300,000
Cash paid for interest						$ 49,681,000	$ 49,133,000
Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Maturity of interest rate swap						Sep. 30, 2016
Variable rate of interest	0.75%			0.75%		0.75%
Interest Rate Swaps [Member] | Combined Interest Rate Cash Flow Hedges On Three Swaps [Member]
Debt Instrument [Line Items]
Number of interest rate swaps held | Swap	4			4		4
Number of interest rate derivatives held with combined notional amount | Swap	3			3		3
Notional amount of interest rate swap	$ 1,000,000,000			$ 1,000,000,000		$ 1,000,000,000
Forward Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Number of interest rate swaps held | Swap								5
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%
Maximum [Member] | Interest Rate Swaps [Member] | Combined Interest Rate Cash Flow Hedges On Three Swaps [Member]
Debt Instrument [Line Items]
Fixed rate of interest on swaps	1.051%			1.051%		1.051%
Minimum [Member] | Interest Rate Swaps [Member] | Combined Interest Rate Cash Flow Hedges On Three Swaps [Member]
Debt Instrument [Line Items]
Fixed rate of interest on swaps	1.049%			1.049%		1.049%
Restrictive Covenants [Member]
Debt Instrument [Line Items]
Restrictive covenants, restricted payments capacity available	$ 120,000,000
Scenario One [Member] | Restrictive Covenants [Member]
Debt Instrument [Line Items]
Maximum Total Leverage Ratio						5.00%
Restricted payment on Senior Secured Credit Facilities						$ 90,000,000
Minimum Total Leverage Ratio						4.50%
Scenario Two [Member] | Restrictive Covenants [Member]
Debt Instrument [Line Items]
Maximum Total Leverage Ratio						4.50%
Restricted payment on Senior Secured Credit Facilities						$ 120,000,000
Minimum Total Leverage Ratio						4.00%
Scenario Three [Member] | Restrictive Covenants [Member]
Debt Instrument [Line Items]
Maximum Total Leverage Ratio						4.00%
Restricted payment on Senior Secured Credit Facilities						$ 120,000,000
Minimum Total Leverage Ratio						3.50%
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
Unamortized debt issuance costs and discounts										6,921,000
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
Discount initially recorded						$ 1,400,000
Debt issuance costs						3,171,000
Unamortized debt issuance costs and discounts	4,110,000			$ 4,110,000		4,110,000
Long-term debt	$ 278,600,000			$ 278,600,000		$ 278,600,000				0
Interest rate, description						Borrowings of Term B-3 Loans bear interest at a fluctuating rate per annum equal to, at SEA’s option, (a) a base rate equal 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” or (b) 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%		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%
Mandatory prepayments				$ 0	$ 0	$ 0	0
Term B-3 Loans [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Repayment of Senior Notes outstanding principal amount			$ 30,000,000
Term B-3 Loans [Member] | Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap									$ 250,000,000
Maturity of interest rate swap						Sep. 30, 2016
Fixed rate of interest on swaps	0.901%			0.901%		0.901%
Variable rate of interest	0.75%			0.75%		0.75%
Term B-3 Loans [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans		0.50%
Term B-3 Loans [Member] | Base Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans		2.25%
Floor rate		1.75%
Term B-3 Loans [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans		3.25%
Floor rate		0.75%
Term B-2 Loans [Member]
Debt Instrument [Line Items]
Debt instrument, balance												$ 1,405,000,000
Long-term debt, maturity date						May 14, 2020
Repayment of Senior Notes outstanding principal amount							31,500,000
Unamortized debt issuance costs and discounts	$ 15,583,000			$ 15,583,000		$ 15,583,000				18,205,000
Long-term debt	$ 1,341,900,000			$ 1,341,900,000		$ 1,341,900,000				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 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						0.25%
Debt instrument interest rate selected percentage	3.00%			3.00%		3.00%
Maximum Total Leverage Ratio						3.25%
Percent of original principal amount on effective date used to calculate aggregate annual amount which will amortize in equal quarterly installments											1.00%
Mandatory prepayments				$ 0	$ 0	$ 0	$ 0
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%
Floor rate						1.75%
Term B-2 Loans [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans						2.25%
Floor rate						0.75%
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%		100.00%
Percentage of net proceeds incurrence of debt						100.00%
First lien secured net leverage ratio						3.50%
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.
Senior Secured Credit Facilities [Member] | Restrictive Covenants [Member]
Debt Instrument [Line Items]
Total Leverage Ratio	4.13%
Senior Secured Credit Facilities [Member] | Scenario One [Member] | Maximum [Member]
Debt Instrument [Line Items]
Percentage of annual excess cash flow used to prepay outstanding loan						25.00%
Senior Secured Credit Facilities [Member] | Scenario One [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]
Unamortized debt issuance costs and discounts	$ 2,648,000			$ 2,648,000		$ 2,648,000				$ 3,862,000
Senior secured revolving	$ 192,500,000			$ 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) a base rate equal 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” or (b) 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.
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%		2.50%
Permitted increased commitments under the Revolving Credit Facility in aggregate principal amount	$ 350,000,000			$ 350,000,000		$ 350,000,000
Commitment fees on unused portion of facility						0.50%
Amount available for borrowing	$ 174,500,000			$ 174,500,000		$ 174,500,000
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%