Equity (Narrative) (Details) $ / shares in Units, $ in Millions				6 Months Ended		9 Months Ended
	Nov. 10, 2015 USD ($) $ / shares shares	Oct. 22, 2014 USD ($) $ / shares shares	Oct. 09, 2014	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($)	Mar. 31, 2015 USD ($) $ / shares shares	Oct. 10, 2015 shares	Jun. 30, 2015 USD ($) $ / shares shares	Oct. 16, 2014 shares	Oct. 10, 2014 $ / shares
Stockholders Equity Note [Line Items]
Common stock, shares issued | shares				244,667,472				243,008,679
Common stock, par value | $ / shares				$ 0.001				$ 0.001		$ 0.001
Stock split ratio			223,000
Common stock, shares outstanding | shares				244,667,472			223,000,000	243,008,679
Common stock issuance costs					$ 22.2
Proceeds from issuance of common stock (net of issuance costs)				$ 387.2
Increase in additional paid-in capital associated with stock-based compensation expense				87.6
Increase to additional paid-in capital associated with a tax benefit from stock-based compensation				5.1
Share based compensation tax difference benefit				0.6
Gross tax benefit recognized as cash inflow in financing activities				7.9
Excess tax benefit from stock-based compensation				(7.9)
Share repurchase and retirement				$ 17.9
Share Repurchase Program Authorized November 10, 2015 [Member]
Stockholders Equity Note [Line Items]
Common stock, shares outstanding | shares				726,327
Repurchase share | shares	355,557
Average share price | $ / shares	$ 23.85
Repurchase Value	$ 8.5
Share repurchase program authorizes	$ 500.0
Share repurchase program authorized period	6 months
Share repurchase program remaining authorized shares								$ 491.5
Amount withheld for tax obligations for vested RSU's	$ 9.4
Shares withheld for tax obligations for vested RSU's | shares	370,770
Federal [Member]
Stockholders Equity Note [Line Items]
Net operating loss carryforward balance				$ 4.5
IPO [Member]
Stockholders Equity Note [Line Items]
Shares Issued, Price Per Share | $ / shares		$ 19.00
Gross proceeds from issuance of common stock		$ 304.2
Common stock issuance costs		$ 22.2
FPO [Member]
Stockholders Equity Note [Line Items]
Proceeds from issuance of common stock, shares | shares						4,000,000
Shares Issued, Price Per Share | $ / shares						$ 27.35
Gross proceeds from issuance of common stock						$ 109.5
Common stock issuance costs						$ 4.3
CII [Member]
Stockholders Equity Note [Line Items]
Common stock, shares issued | shares									1,000
Common stock, par value | $ / shares				$ 0.001
Parent Company [Member]
Stockholders Equity Note [Line Items]
Proceeds from issuance of common stock, shares | shares		16,008,679