Business Acquisitions (Details textual) - USD ($) $ in Thousands			3 Months Ended
	Apr. 03, 2018	Mar. 26, 2018	Jun. 30, 2018	Jan. 01, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill			$ 903,849	$ 909,811	$ 909,811
Fishing Hot Spots [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred		$ 7,100
Payments for Purchase of Other Assets		$ 6,800
Other minority interest investments [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred			$ 9,500
Fishidy [Member]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred	$ 7,100
Payments for Purchase of Other Assets	$ 7,100
Consumer and Small and Medium-Sized Security Business [Member] | Held-for-sale [Member]
Business Acquisition [Line Items]
Carrying amount of disposal group					$ 28,800