Financial Statements (Details) - USD ($) $ / shares in Units, $ in Thousands							9 Months Ended
	May 06, 2016	May 03, 2016	May 02, 2016	Feb. 24, 2016	Feb. 22, 2016	Feb. 19, 2016	Sep. 30, 2016	Sep. 30, 2015
Class of Stock [Line Items]
Proceeds from sale of common stock in the Offering							$ 1,225,999	$ 0
Credit Suisse Securities (USA) LLC and J.P. Morgan Securities LLC
Class of Stock [Line Items]
Number of shares purchased in the Offering (in shares)		1,575,000	10,500,000
Share price (in dollars per share)			$ 67.00
Proceeds from sale of common stock in the Offering	$ 795,600
Goldman, Sachs & Co.
Class of Stock [Line Items]
Number of shares purchased in the Offering (in shares)					975,000	6,500,000
Share price (in dollars per share)						$ 58.50
Proceeds from sale of common stock in the Offering				$ 430,400