Condensed Consolidated Statements of Cash Flows (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Cash flows from operating activities:
Net earnings	$ 26,421	$ 21,411
Adjustments to reconcile net earnings to net cash provided by operating activities:
Depreciation and amortization	14,710	15,729
Amortization of debt issuance costs	518	478
Provision for losses on accounts receivable	543	931
Loss on extinguishment of debt	0	2,782
(Gain) loss on derivatives, net	(178)	1,076
Gain (loss) on sale of property, plant and equipment	(79)	40
Stock-based compensation expense	2,287	1,912
Deferred income taxes	(1,004)	(1,944)
Changes in assets and liabilities:
Accounts receivable, net	30,767	53,429
Inventories	7,184	2,334
Prepaid expenses and other	10,939	1,351
Other assets	873	(1,352)
Accounts payable	(52,505)	(43,914)
Progress billings	(4,156)	7,255
Accrued expenses	31,629	30,610
Other non-current liabilities	637	2,320
Total adjustments	(12,047)	(3,445)
Net cash provided by (used in) operating activities	14,374	17,966
Cash flows from investing activities:
Additions to property, plant and equipment	(9,265)	(5,024)
Proceeds from sale of property, plant and equipment	79	20
Proceeds from sale of available-for-sale securities	0	1,494
Net cash used in investing activities	(9,186)	(3,510)
Net Cash Provided by (Used in) Financing Activities [Abstract]
Proceeds from Issuance of Debt	0	260,000
Repayments of long-term debt	(3,750)	(243,989)
Debt issuance costs	0	(4,880)
Repurchases of common stock	(1,366)	(45,530)
Proceeds from issuance of common stock	5,685	3,133
Net cash provided (used in) by financing activities	569	(31,266)
Effect of exchange rate changes on cash and cash equivalents	(529)	1,066
Net increase (decrease) in cash and cash equivalents	5,228	(15,744)
Cash and cash equivalents at beginning of period	101,971	245,935
Cash and cash equivalents at end of period	107,199	230,191
Supplemental disclosure of cash flow information:
Cash paid during the period for interest	11,192	12,819
Cash paid during the period for income taxes	7,630	8,445
Non-cash financing activities:
Stock issued under stock-based compensation plans	$ 0	$ 1,193