XML 41 R81.htm IDEA: XBRL DOCUMENT v2.4.1.9
Other Assets - Summary of Amortization Expense Related to the Intangibles, Excluding Above and Below-Market Leases (Detail) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Dec. 31, 2014
Dec. 31, 2013
Dec. 31, 2012
Intangible Assets Net Excluding Goodwill [Abstract]      
Amortization expense $ 109.5us-gaap_AmortizationOfIntangibleAssets $ 57.0us-gaap_AmortizationOfIntangibleAssets $ 17.5us-gaap_AmortizationOfIntangibleAssets