Long-Term Debt - Additional Information (Detail) (USD $)	3 Months Ended		12 Months Ended	0 Months Ended	1 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014	Apr. 07, 2015	Apr. 30, 2015	Dec. 01, 2009	May 14, 2013
Debt Instrument [Line Items]
Deferred financing costs, net	$ 18,220,000		$ 20,003,000
Long-term debt	1,638,925,000		1,612,438,000
Effective interest rate	3.00%
Commitment fees on unused portion of facility	0.50%
Mandatory prepayments	0		0
Outstanding letters of credit	18,000,000
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	36,300,000
Restrictive covenants, restricted payments capacity remaining	83,700,000
Cash paid for interest	11,347,000	11,253,000
On or After December 1, 2014 [Member]
Debt Instrument [Line Items]
Redemption price for Senior Notes Percentage	105.50%
On or After December 1, 2015 [Member]
Debt Instrument [Line Items]
Redemption price for Senior Notes Percentage	102.75%
Senior Notes [Member]
Debt Instrument [Line Items]
Debt instrument, balance						400,000,000
Long-term debt, maturity date	Dec. 01, 2016
Long-term debt	260,000,000		260,000,000
Debt instrument interest rate	11.00%
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	1,348,925,000		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 leverage ratio.
Basis point step down on applicable margin upon achievement of certain leverage ratio	0.25%
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] | 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%
Percentage of net proceeds incurrence of debt	100.00%
First lien secured net leverage ratio	3.50%
Term B-3 Loans [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Debt instrument, balance				280,000,000
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".
Redemption price for Senior Notes Percentage				105.50%
Term B-3 Loans [Member] | Subsequent Event [Member] | Federal Funds Rate [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans				0.50%
Term B-3 Loans [Member] | Subsequent Event [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] | Subsequent Event [Member] | LIBOR Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans				3.25%
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%
Interest Rate Swaps [Member] | Maximum [Member]
Debt Instrument [Line Items]
Fixed rate of interest on swaps	1.051%
Interest Rate Swaps [Member] | Minimum [Member]
Debt Instrument [Line Items]
Fixed rate of interest on swaps	1.049%
Interest Rate Swaps [Member] | Term B-2 Loans [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap		450,000,000
Maturity of interest rate swap	Sep. 30, 2016
Fixed rate of interest on swaps	1.051%
Variable rate of interest	0.75%
Interest Rate Swaps [Member] | Term B-3 Loans [Member] | Subsequent Event [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap					250,000,000
Maturity of interest rate swap					Sep. 30, 2016
Interest Rate Swap One [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap	275,000,000
Interest Rate Swap Two [Member]
Debt Instrument [Line Items]
Notional amount of interest rate swap	275,000,000
Combined Interest Rate Cash Flow Hedges On Two Swaps [Member] | Interest Rate Swaps [Member]
Debt Instrument [Line Items]
Number of interest rate swap held	2
Notional amount of interest rate swap	550,000,000
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 Agreement [Member]
Debt Instrument [Line Items]
Senior secured revolving	192,500,000
Long-term debt	30,000,000
Amounts of outstanding long-term debt	30,000,000
Line of credit facility, interest rate	2.64%
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%
Effective interest rate	2.50%
Permitted increased commitments under the Revolving Credit Facility in aggregate principal amount	350,000,000
Letters of credit available amount	144,500,000
Revolving Credit Agreement [Member] | Base Rate Loan [Member]
Debt Instrument [Line Items]
Applicable margin for Term Loans	1.75%
Revolving Credit Agreement [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	4.18%
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%