Shareholders' Equity (Details)			1 Months Ended	3 Months Ended
	Jun. 16, 2015 USD ($) $ / shares shares	Mar. 18, 2015 $ / shares shares	Apr. 30, 2015 USD ($) shares	Jun. 30, 2015 USD ($) $ / shares shares	Mar. 31, 2015 $ / shares shares	Oct. 31, 2014 class $ / shares shares
Shareholders' Equity
Number of classes of stock authorized | class						1
Common shares authorized (in shares)		1,000,000,000		1,000,000,000	1,000,000,000	10,000
Common shares issued (in shares)		75,000,000		99,150,000	75,000,000
Common shares outstanding (in shares)		75,000,000		99,150,000	75,000,000
Common shares par value (in dollars per share) | $ / shares		$ 0.00001		$ 0.00001	$ 0.00001	$ 1.00
Stock split ratio		100,000
Sale of common stock in IPO (in shares)	24,150,000
Sale of common stock in IPO (price per share) | $ / shares	$ 15.00			$ 15.00
Sale of common stock in IPO, exercise of underwriters' option to purchase additional shares (in shares)	3,150,000
Gross proceeds from IPO | $	$ 362,250,000
Net proceeds from IPO, net of underwriting discounts and commissions and offering expenses | $	334,502,000
Underwriting discounts, commissions and offering expenses | $	$ 27,748,000			$ 27,748,000
Capital contribution | $				$ 750,000
Before Stock Split
Shareholders' Equity
Common shares authorized (in shares)		10,000
Common shares issued (in shares)		750
Common shares outstanding (in shares)		750
Common shares par value (in dollars per share) | $ / shares		$ 1.00
RSL
Shareholders' Equity
Additional shares issued			0
Capital contribution | $			$ 750,000