Subsequent Events - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	1 Months Ended
	Jul. 17, 2012 PMI [Member]	Jul. 17, 2012 WMMRC [Member]	Mar. 01, 2013 First Lien Note [Member] Subsequent Events [Member]
Subsequent Event [Line Items]
Cash paid to stockholders			$ 25.0
Interest paid on Notes			3.7
Principal payment on Notes			21.3
Amount paid by PMI	$ 49.0	$ 30.7