Selected Quarterly Financial and Supplementary Data - Unaudited (Details) - USD ($) shares in Thousands, $ in Thousands	3 Months Ended																12 Months Ended
	Dec. 31, 2015	[1]	Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015		Dec. 31, 2014	[2]	Sep. 30, 2014	[3]	Jun. 30, 2014	[4]	Mar. 31, 2014	[5]	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Total Gross sales	$ 156,943		$ 92,350		$ 106,379		$ 78,184		$ 128,841		$ 81,145		$ 97,972		$ 66,192		$ 433,856	$ 374,150	$ 317,212
Net revenues	156,187		92,979		106,635		77,525		129,315		81,300		97,893		66,105		433,326	374,613	318,176
Gross profit	66,261		35,680		45,945		29,079		45,399		28,406		33,415		16,578		176,965	123,798	102,904
Income from continuing operations	17,482		11,876		19,450		8,368		28,258		8,882		19,827		1,166		57,176	58,133	30,275
Loss from discontinued operations	332	[6]	(129)	[6]	213	[6]	(375)	[6]	(373)	[6]	(113)	[6]	(160)	[6]	(184)	[6]	41	(830)	(4,360)
Net income	$ 17,814		$ 11,747		$ 19,663		$ 7,993		$ 27,885		$ 8,769		$ 19,667		$ 982		$ 57,217	$ 57,303	$ 25,915
Basic (in dollars per share)	$ 0.56	[7]	$ 0.37	[7]	$ 0.63	[7]	$ 0.26	[7]	$ 0.90	[7]	$ 0.28	[7]	$ 0.64	[7]	$ 0.03	[7]	$ 1.82	$ 1.86	$ 0.86
Diluted (in dollars per share)	$ 0.54	[7]	$ 0.36	[7]	$ 0.61	[7]	$ 0.25	[7]	$ 0.88	[7]	$ 0.28	[7]	$ 0.63	[7]	$ 0.03	[7]	$ 1.76	$ 1.81	$ 0.84
Basic (in shares)	31,661	[7]	31,471	[7]	31,344	[7]	31,198	[7]	31,053	[7]	30,801	[7]	30,647	[7]	30,546	[7]	31,420	30,763	30,150
Diluted (in shares)	32,784	[7]	32,593	[7]	32,440	[7]	32,158	[7]	31,803	[7]	31,599	[7]	31,428	[7]	31,408	[7]	32,555	31,643	30,901

[1] Income from continuing operations includes restructuring expenses of $15,573 and a tax benefit of $1,464 related to the decision to sell our finished dosage form facility in Hyderabad, India.

[2] Income from continuing operations includes a gain on sale of land of $1,234 and a corresponding tax expense of $387, a benefit of $11,719 for the reversal of a valuation allowance on deferred tax assets, a benefit of $3,948 for favorable audit settlements, and expense of $7,170 related to a voluntary lump sum pension settlement.

[3] Income from continuing operations includes the reversal of a valuation allowance on deferred tax assets of $824.

[4] Income from continuing operations includes the reversal of a valuation allowance on deferred tax assets of $14,161 and a loss of $4,122 related to the purchase of the remaining shares in Zenara.

[5] Income from continuing operations includes the reversal of a valuation allowance on deferred tax assets of $198.

[6] Discontinued operations include charges for environmental remediation related to sites of divested businesses.

[7] Earnings per share calculations for each of the quarters are based on the weighted average number of shares outstanding for each period. As such, the sum of the quarters may not necessarily equal the earnings per share amount for the year.