Convertible Perpetual Preferred Stock (Tables)

12 Months Ended

Dec. 31, 2015

Convertible Perpetual Preferred Stock [Abstract]

Summary of Activity, Convertible Perpetual Preferred Stock

The following is a summary of the activity related to our Convertible perpetual preferred stock from December 31, 2012 to December 31, 2015 (in millions, except share data):

	Number of Shares Outstanding		Amount
Balance as of December 31, 2012	353,355		$	342.2
Repurchase of preferred stock	(257,110	)	(249.0		)
Balance as of December 31, 2013 and 2014	96,245		93.2
Conversion of preferred stock	(96,245	)	(93.2		)
Balance as of December 31, 2015	—		$	—

Summary Allocation of Consideration Exchanged, Convertible Perpetual Preferred Stock

The allocation of the consideration exchanged for repurchases of preferred stock is as follows (in millions):

	For the Year Ended December 31, 2013
Carrying value of shares repurchased	$	249.0
Cumulative dividends included as part of repurchase price	2.2
Excess exchanged in transaction	71.6
	$	322.8