Guarantor and Nonguarantor Financial Statements - Condensed Consolidating Statement of Cash Flows (Parenthetical) (Detail)	Dec. 31, 2016	Dec. 31, 2015	Aug. 13, 2015	Dec. 31, 2014	Dec. 12, 2014	Sep. 26, 2014
4.875% Senior Notes [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Debt instrument, interest rate	4.875%	4.875%	4.875%
4.875% Senior Notes [Member] | CBRE [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Debt instrument, interest rate		4.875%
5.25% Senior Notes [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Debt instrument, interest rate	5.25%	5.25%		5.25%	5.25%	5.25%
5.25% Senior Notes [Member] | CBRE [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Debt instrument, interest rate				5.25%
6.25% Senior Notes [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Debt instrument, interest rate				6.25%
6.25% Senior Notes [Member] | CBRE [Member]
Condensed Cash Flow Statements, Captions [Line Items]
Debt instrument, interest rate				6.25%