Segment Information (Schedule of Segment Perfomance Measures by Segment) (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended								12 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Net sales	$ 139,580	$ 124,830	$ 116,508	$ 129,261	$ 123,115	$ 150,871	$ 113,956	$ 111,748	$ 510,179	$ 499,690	$ 444,388
Gross profit	29,022	24,963	26,984	33,734	24,531	31,527	20,708	21,505	114,703	98,271	82,032
Income before income taxes									44,674	34,550	24,740
Operating Segments | Human Health
Segment Reporting Information [Line Items]
Net sales									160,217	129,667	105,249
Gross profit									48,496	39,306	29,932
Income before income taxes									19,710	17,276	11,683
Operating Segments | Pharmaceutical Ingredients
Segment Reporting Information [Line Items]
Net sales									176,425	184,852	162,998
Gross profit									36,615	31,367	25,472
Income before income taxes									17,557	13,294	8,066
Operating Segments | Performance Chemicals
Segment Reporting Information [Line Items]
Net sales									173,537	185,171	176,141
Gross profit									29,592	27,598	26,628
Income before income taxes									13,273	10,400	10,570
Unallocated Corporate
Segment Reporting Information [Line Items]
Net sales
Gross profit
Income before income taxes									$ (5,866)	$ (6,420)	$ (5,579)