Stockholders' Equity and Acquisitions - Stockholders’ Equity (Detail) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
	Jan. 15, 2003	Dec. 31, 2014	Dec. 31, 2003	Dec. 31, 2015
Equity [Abstract]
Common stock, shares issued (in shares)	59,600,000	83,209,293		83,209,293
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01		$ 0.01
Common stock, per share (in dollars per share)	$ 10.00
Proceeds from issuance of common stock	$ 567.2
Cash donated			$ 4.8
Number of shares donated			1,920,000
Value of shares donated			$ 24.0
Liquidation date		Dec. 31, 2015
Liquidation account balance		$ 13.9