Acquisitions - Textual (Details) - USD ($)		3 Months Ended		12 Months Ended
	Jan. 01, 2018	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Income attributable to fair value adjustments				$ (374,000)	$ (4,819,000)	$ 8,227,000
Share-based Compensation		$ 1,534,000	$ 7,480,000	18,416,000	24,350,000	21,003,000
Goodwill, Written off Related to Sale of Business Unit					17,593,000
Goodwill				37,592,000	0
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				$ (25,550,000)		(8,936,000)
Intangible assets amortization period (years)				7 years
Stock-based compensation expense				$ 7,191,000	9,294,000
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings				3,512,000	3,273,000
Stock Issued During Period, Value, Acquisitions						34,219,000
Business Combination, Contingent Consideration, Liability		83,695,000	122,426,000	83,695,000	122,426,000
Noncontrolling Interest, Increase from Business Combination				0	1,666,000
Asset Impairment Charges		56,732,000		80,057,000	4,415,000	48,524,000
Goodwill		740,955,000	835,935,000	740,955,000	835,935,000	$ 844,759,000
Aggregate 2018 Step-up Transaction [Member] [Member]
Business Acquisition [Line Items]
Cost of acquired entity, cash paid				3,000
Deferred acquisition consideration		$ 4,305		4,305
Allison & Partners LLC [Member]
Business Acquisition [Line Items]
Percentage of voting interests acquired	24.50%
Business Combination, Consideration Transferred				10,000
Cost of acquired entity, cash paid				0
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination	$ 20,096
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				9,000
Business Combination, Contingent Consideration, Liability	$ 10,000
Noncontrolling Interest, Increase from Business Combination				$ 1,000
Aggregate 2017 Step Up Transactions [Domain]
Business Acquisition [Line Items]
Share-based Compensation					996
Cost of acquired entity, cash paid					3,858
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests					11,965
Business Combination, Contingent Consideration, Liability			7,208		7,208
Business Combination, Acquisition of Less than 100 Percent, Redeemable Noncontrolling Interest, Fair Value					816
Noncontrolling Interest, Period Increase (Decrease)					397
Noncontrolling Interest, Increase from Business Combination					2,315
Aggregate 2017 Dispositions [Domain]
Business Acquisition [Line Items]
Share-based Compensation					2,000
Goodwill, Written off Related to Sale of Business Unit					17,593
Noncontrolling Interest, Decrease from Deconsolidation					10,657,000
OneChocolate [Domain]
Business Acquisition [Line Items]
Percentage of voting interests acquired		100.00%		100.00%
Business Combination, Consideration Transferred				$ 3,231
Deferred acquisition consideration		$ 2,146		2,146
Working capital payments		$ 966		$ 966
Instrument [Domain]
Business Acquisition [Line Items]
Percentage of voting interests acquired		51.00%		51.00%
Business Combination, Consideration Transferred				$ 35,591
Cost of acquired entity, cash paid				29,000
Noncontrolling Interest, Increase from Business Combination				27,357
Business Combination, Consideration Transferred, Other				10,304
Finite-lived Intangible Assets Acquired				23,130
Goodwill		$ 32,776		$ 32,776
Doner [Domain]
Business Acquisition [Line Items]
Percentage of voting interests acquired		14.90%		14.90%
Business Combination, Consideration Transferred, Including Equity Interest in Acquiree Held Prior to Combination				$ 16,361
Kingsdale Partners, LP
Business Acquisition [Line Items]
Asset Impairment Charges				$ 5,000
Source [Domain]
Business Acquisition [Line Items]
Percentage of voting interests acquired		3.00%		3.00%
Doner and Source [Domain]
Business Acquisition [Line Items]
Business Combination, Consideration Transferred				$ 7,618
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				12,000
Business Combination, Acquisition of Less than 100 Percent, Redeemable Noncontrolling Interest, Fair Value				$ 1,000
Noncontrolling Interest Equity [Domain] | Aggregate 2017 Dispositions [Domain]
Business Acquisition [Line Items]
Noncontrolling Interest, Increase from Sale of Parent Equity Interest					$ 6,961
Common Stock
Business Acquisition [Line Items]
Stock Issued During Period, Shares, Acquisitions				108,898	(161,535)	1,900,000
Redeemable Noncontrolling Interest [Member] | Aggregate 2017 Dispositions [Domain]
Business Acquisition [Line Items]
Redeemable Noncontrolling Interest, Increase from Sale of Equity Interest					$ 1,690
Additional Paid-in Capital
Business Acquisition [Line Items]
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				$ (10,140,000)	(2,315,000)	$ (22,776,000)
Stock Issued During Period, Value, Acquisitions				7,030,000		34,219,000
Noncontrolling Interest, Increase from Business Combination					(5,654,000)
Noncontrolling Interest [Member]
Business Acquisition [Line Items]
Noncontrolling Interest, Decrease from Redemptions or Purchase of Interests				(15,410,000)	11,965,000	13,840,000
Noncontrolling Interest, Increase from Business Combination					12,614,000
Noncontrolling Interest [Member] | Aggregate 2017 Dispositions [Domain]
Business Acquisition [Line Items]
Noncontrolling Interest, Decrease from Deconsolidation					10,657,000
Contingent Payment [Member]
Business Acquisition [Line Items]
Income attributable to fair value adjustments		$ 8,979,000	18,173,000	(3,679,000)	(6,021,000)
Fixed payments [Member]
Business Acquisition [Line Items]
Business Combination, Contingent Consideration, Liability		$ 1,097,000	$ 3,340,000	$ 1,097,000	3,340,000
Common Class A | Common Stock | Instrument [Domain]
Business Acquisition [Line Items]
Stock Issued During Period, Shares, Acquisitions				1,011,561
Stock Issued During Period, Value, Acquisitions				$ 7,030
Common Class A | Common Stock | Forsman & Bodenfors AB [Domain]
Business Acquisition [Line Items]
Stock Issued During Period, Value, Acquisitions				7,030,000	$ 0	$ 34,219,000
Three subsidiaries
Business Acquisition [Line Items]
Disposal Group, Not Discontinued Operation, Gain (Loss) on Disposal				$ 1,732,000