| Schedule of Segment Reporting Information, by Segment [Table Text Block] |
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Net sales: | | | | | | | | | | | | | | | | | | Protein Sciences | | $ | 137,935 | | | $ | 123,187 | | | $ | 399,787 | | | $ | 348,442 | | | Diagnostics and Genomics | | | 47,134 | | | | 40,929 | | | | 123,144 | | | | 114,604 | | | Intersegment | | | (208 | ) | | | (143 | ) | | | (590 | ) | | | (307 | ) | | Consolidated net sales | | $ | 184,861 | | | $ | 163,973 | | | $ | 522,341 | | | $ | 462,739 | | | Operating income: | | | | | | | | | | | | | | | | | | Protein Sciences | | $ | 62,256 | | | $ | 53,813 | | | $ | 175,821 | | | $ | 150,240 | | | Diagnostics and Genomics | | | 3,579 | | | | 9,649 | | | | 5,061 | | | | 22,816 | | | Segment operating income | | $ | 65,835 | | | $ | 63,462 | | | $ | 180,882 | | | $ | 173,056 | | | Costs recognized on sale of acquired inventory | | | (935 | ) | | | (1,431 | ) | | | (2,804 | ) | | | (2,013 | ) | | Amortization of acquisition related intangible assets | | | (14,400 | ) | | | (11,872 | ) | | | (43,678 | ) | | | (34,547 | ) | | Acquisition related expenses | | | - | | | | (1,312 | ) | | | (2,973 | ) | | | (23,994 | ) | | Stock based compensation | | | (5,725 | ) | | | (4,748 | ) | | | (24,151 | ) | | | (13,587 | ) | | Corporate general, selling, and administrative expenses | | | (685 | ) | | | (1,015 | ) | | | (3,821 | ) | | | (5,652 | ) | | Consolidated operating income | | $ | 44,090 | | | $ | 43,084 | | | $ | 103,455 | | | $ | 93,263 | | |