Schedule of Dividends Declared (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Stockholders' Equity [Abstract]
Dividends declared	$ 11,811	$ 12,029	$ 34,965	$ 37,229
Dividend per share	$ 0.25	$ 0.25	$ 0.75	$ 0.75