Total Capital Commitments, Unfunded Capital Commitments, and Our Ownership in Each Fund (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Venture Capital and Private Equity Fund Investments [Line Items]
Unfunded Commitments	$ 4,504
Strategic Investors Fund, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Unfunded Commitments	1,338
Capital Preferred Return Fund, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Unfunded Commitments	1,603
Growth Partners, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Unfunded Commitments	1,563
Parent Company
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	468,440
Unfunded Commitments	18,067
Parent Company | CP I, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	6,000
Unfunded Commitments	$ 270
Ownership percentage of each Fund	10.70%
Parent Company | CP II, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 1,200
Unfunded Commitments	$ 162
Ownership percentage of each Fund	5.10%
Parent Company | Shanghai Yangpu Venture Capital Fund (LP)
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 835
Unfunded Commitments	$ 0
Ownership percentage of each Fund	6.80%
Parent Company | Strategic Investors Fund, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 15,300
Unfunded Commitments	$ 688
Ownership percentage of each Fund	12.60%
Parent Company | Strategic Investors Fund II, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 15,000
Unfunded Commitments	$ 1,050
Ownership percentage of each Fund	8.60%
Parent Company | Strategic Investors Fund III, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 15,000
Unfunded Commitments	$ 1,275
Ownership percentage of each Fund	5.90%
Parent Company | Strategic Investors Fund IV, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 12,239
Unfunded Commitments	$ 2,325
Ownership percentage of each Fund	5.00%
Parent Company | Strategic Investors Fund V Funds
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 515
Unfunded Commitments	141
Parent Company | Capital Preferred Return Fund, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	12,688
Unfunded Commitments	$ 0
Ownership percentage of each Fund	20.00%
Parent Company | Growth Partners, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 24,670
Unfunded Commitments	$ 1,340
Ownership percentage of each Fund	33.00%
Parent Company | Other private equity fund
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 9,338
Unfunded Commitments	$ 0
Ownership percentage of each Fund	58.20%
Parent Company | Debt Funds (Equity Method Accounting)
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	$ 58,021
Unfunded Commitments	0
Parent Company | Other Fund Investments
Venture Capital and Private Equity Fund Investments [Line Items]
Capital Commitments	297,634
Unfunded Commitments	$ 10,816
Fair value accounting | Venture capital and private equity fund investments | Strategic Investors Fund, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	12.60%	12.60%
Fair value accounting | Venture capital and private equity fund investments | Strategic Investors Fund II, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	8.60%	8.60%
Fair value accounting | Venture capital and private equity fund investments | Strategic Investors Fund III, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	5.90%	5.90%
Fair value accounting | Venture capital and private equity fund investments | Strategic Investors Fund IV, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	5.00%	5.00%
Fair value accounting | Venture capital and private equity fund investments | Capital Preferred Return Fund, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	20.00%	20.00%
Fair value accounting | Venture capital and private equity fund investments | Growth Partners, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	33.00%	33.00%
Fair value accounting | Venture capital and private equity fund investments | Other private equity fund
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	58.20%	58.20%
Fair value accounting | Venture capital and private equity fund investments | Direct ownership interest | CP II, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	1.30%
Fair value accounting | Venture capital and private equity fund investments | Direct ownership interest | Other private equity fund
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	41.50%
Fair value accounting | Venture capital and private equity fund investments | Indirect ownership interest | CP II, L.P.
Venture Capital and Private Equity Fund Investments [Line Items]
Ownership percentage of each Fund	3.80%