Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Operating Activities
Net income	$ 36,268	$ 27,456
Adjustments to reconcile net income to net cash (used in) provided by operating activities:
Depreciation and amortization	7,322	7,660
Deferred income taxes	(589)
Stock-based compensation	2,717	2,455
Gain on disposal of property, plant and equipment	(3)	(48)
Excess tax benefits from stock compensation	(1,771)	(12,533)
Other non-cash adjustments	(270)	(245)
Changes in operating assets and liabilities:
Accounts receivable	(88,074)	(22,794)
Inventories	5,121	1,373
Prepaid expenses and other assets	979	(206)
Accounts payable	(104)	4,583
Accrued expenses and other liabilities	(856)	(6,007)
Income taxes receivable/payable	11,360	9,764
Net cash (used in) provided by operating activities	(27,900)	11,458
Investing Activities
Expenditures for property, plant and equipment	(14,088)	(4,927)
Proceeds from sales of property, plant and equipment	3	48
Purchase of acquired company, net of cash acquired	(31)	(44)
Notes receivable, net		39
Net cash used in investing activities	(14,116)	(4,884)
Financing Activities
Borrowings under line of credit	118,000	120,000
Principal payments under line of credit	(80,500)	(85,000)
Repurchases of common stock	(2,847)	(52,892)
Proceeds from employee stock purchase and option plans	197	585
Excess tax benefits from stock compensation	1,771	12,533
Net cash provided by (used in) financing activities	36,621	(4,774)
Net (decrease) increase in cash and cash equivalents	(5,395)	1,800
Cash and cash equivalents at beginning of period	9,544	3,772
Cash and cash equivalents at end of period	4,149	5,572
Supplemental Disclosure:
Cash paid for interest, net of capitalized interest	284	384
Cash paid for income taxes, net	$ 10,342	$ 6,783