Subsequent Events - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions			1 Months Ended	3 Months Ended	6 Months Ended
	May. 06, 2015	Feb. 18, 2015	Aug. 31, 2015	Sep. 30, 2015	Jun. 30, 2015
Subsequent Event [Line Items]
Cash dividend declared per common share	$ 0.10	$ 0.10
Common stock dividends payable, date declared					Aug. 05, 2015
Common stock dividends payable, date to be paid					Sep. 03, 2015
Common stock dividends payable, date of record					Aug. 17, 2015
Scenario Forecast [Member] | Special Termination Benefits [Member]
Subsequent Event [Line Items]
Compensation expense related to special termination benefits				$ 2.8
Subsequent Events [Member]
Subsequent Event [Line Items]
Cash dividend declared per common share			$ 0.10