Commitments, Contingencies and Guarantees - Textual (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	$ 60,180,000	$ 69,471,000
Letters of credit outstanding, amount	4,360,000
Operating leases, rent expense	56,725,000	47,583,000	$ 42,657,000
Operating leases, income statement, sublease revenue	3,027,000	$ 1,739,000	$ 1,449,000
Future sublease income receivable	11,599,000
Contractual redemption right [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	12,510,000
Termination or Death Redemption Right [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	43,085,000
Excess Initial Redemption Value [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	4,585,000
Common Class A | Contractual redemption right [Member]
Temporary Equity [Line Items]
Redeemable Noncontrolling Interest, Equity, Redemption Value	124,000
Investments [Member]
Temporary Equity [Line Items]
Investment commitments	$ 738,000
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