Schedule I - Dividends from Subsidiary - Schedule of SEA Paid a Cash Dividend to Parent Related to Dividend Declarations (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Q4 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Jan. 22, 2016
Q1 2016 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Apr. 01, 2016
Q2 2016 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Jul. 01, 2016
Q3 2016 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Oct. 07, 2016
Q4 2014 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Jan. 22, 2015
Q1 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Apr. 01, 2015
Q2 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Jul. 01, 2015
Q3 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Oct. 06, 2015
Parent Company [Member] | Q4 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Jan. 22, 2016
Cash dividends paid	$ 17,808
Parent Company [Member] | Q1 2016 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Apr. 01, 2016
Cash dividends paid	$ 21,269
Parent Company [Member] | Q2 2016 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Jul. 01, 2016
Cash dividends paid	$ 18,176
Parent Company [Member] | Q3 2016 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date	Oct. 07, 2016
Cash dividends paid	$ 8,647
Parent Company [Member] | Q4 2014 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Jan. 22, 2015
Cash dividends paid		$ 18,112
Parent Company [Member] | Q1 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Apr. 01, 2015
Cash dividends paid		$ 18,204
Parent Company [Member] | Q2 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Jul. 01, 2015
Cash dividends paid		$ 18,238
Parent Company [Member] | Q3 2015 Declaration [Member]
Dividends Payable [Line Items]
Cash dividends payable date		Oct. 06, 2015
Cash dividends paid		$ 18,117