Fair Value Measurements (Tables)

9 Months Ended

Sep. 30, 2015

Fair Value Disclosures [Abstract]

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis

The following table categorizes by level in the fair value hierarchy the estimated fair value at September 30, 2015 and December 31, 2014 of our assets and liabilities that are measured at fair value on a recurring basis ($ in millions):

		September 30, 2015			December 31, 2014
		Level 2		Level 3	Level 2		Level 3
Assets
	Foreign currency forward contracts receivable	$	2.7	—	$	10.5	—
	Deferred compensation plan assets	128.9		—	111.2		—
	Investments in real estate ventures - fair value	—		150.3	—		113.6
Total assets at fair value		$	131.6	150.3	$	121.7	113.6
Liabilities
	Foreign currency forward contracts payable	$	15.2	—	$	18.2	—
	Deferred compensation plan liabilities	124.5		—	107.9		—
Total liabilities at fair value		$	139.7	—	$	126.1	—