Other Assets, Net - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Accumulated amortization of other assets	$ 45.9		$ 44.0
Amortization of intangible assets	0.6	0.2
Allowances Straight-line rent receivables	$ 4.1		$ 3.8