Commitments, Contingencies and Guarantees - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2017
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	$ 60,180,000			$ 62,886,000
Letters of credit outstanding, amount	5,056,000			5,056,000
Operating leases, rent expense	64,086,000	$ 56,725,000	$ 47,583,000
Operating leases, income statement, sublease revenue	2,797,000	$ 3,027,000	$ 1,739,000
Future sublease income receivable				$ 17,369,000
Contractual redemption right [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	15,864,000
Termination or Death Redemption Right [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	41,748,000
Excess Initial Redemption Value [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	5,272,000
Common Class A | Contractual redemption right [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	184,000
Investments [Member]
Temporary Equity [Line Items]
Investment commitments	$ 148,000
Minimum [Member]
Temporary Equity [Line Items]
Redeemable noncontrolling interest obligation, year of payment	2017
Maximum
Temporary Equity [Line Items]
Redeemable noncontrolling interest obligation, year of payment	2023
SEC Investigation [Member]
Temporary Equity [Line Items]
Civil penalty	$ 1,500