| Schedule of Segment Reporting Information, by Segment [Table Text Block] |   |   |   |  |   |   |  |   |   |   |   |  |   |   |  |   |   |   |   |  |   |   |  |   |   |  |   |   |  |   |   |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  | $ | 85,953 |  |  | $ | 75,854 |  |  | $ | 172,740 |  |  | $ | 151,597 |  |   |  |  |  | 24,330 |  |  |  | 25,723 |  |  |  | 48,563 |  |  |  | 46,085 |  |   |  |  |  | 21,548 |  |  |  | 19,337 |  |  |  | 41,121 |  |  |  | 35,634 |  |   |  |  |  | (24 |  |  |  | (7 |  |  |  | (36 |  |  |  | (28 |  |   |  |  | $ | 131,807 |  |  | $ | 120,907 |  |  | $ | 262,388 |  |  | $ | 233,288 |  |   | Segment operating income: |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |  |   |  |  | $ | 39,474 |  |  | $ | 39,986 |  |  | $ | 81,954 |  |  | $ | 79,302 |  |   |  |  |  | 5,801 |  |  |  | 7,297 |  |  |  | 12,104 |  |  |  | 12,010 |  |   |  |  |  | 1,843 |  |  |  | 1,528 |  |  |  | 2,052 |  |  |  | 356 |  |   | Subtotal reportable segments |  |  | 47,118 |  |  |  | 48,811 |  |  |  | 96,110 |  |  |  | 91,668 |  |   | Costs recognized on sale of acquired inventory |  |  | (3,848 |  |  |  | (1,245 |  |  |  | (8,069 |  |  |  | (2,357 |  |   | Amortization of acquisition related intangible assets |  |  | (11,627 |  |  |  | (7,361 |  |  |  | (21,815 |  |  |  | (14,772 |  |   | Acquisition related expenses |  |  | (10,732 |  |  |  | (670 |  |  |  | (15,101 |  |  |  | (970 |  |   |  |  |  | (4,055 |  |  |  | (2,321 |  |  |  | (7,245 |  |  |  | (4,359 |  |   | Corporate general, selling, and administrative |  |  | (710 |  |  |  | (1,189 |  |  |  | (2,293 |  |  |  | (2,156 |  |   | Consolidated operating income |  | $ | 16,146 |  |  | $ | 36,025 |  |  | $ | 41,587 |  |  | $ | 67,054 |  |  |