CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Operating Activities:
Net income	$ 67,394	$ 47,469	$ 36,607
Adjustments to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization expense	32,739	26,186	19,208
Deferred income taxes	18,788	15,985	9,530
Stock-based compensation	6,222	7,022	9,236
Amortization of debt costs	6,590	5,768	5,399
Investment gains and losses, net	0	0	3,300
Other	(1,703)	(2,113)	(3,933)
Changes in assets and liabilities, net of business acquisition:
Receivables	(6,969)	(117,083)	3,629
Inventories	(8,118)	(17,555)	(5,228)
Other assets	(37,346)	(4,585)	(13,203)
Accounts payable and accrued expenses	(14,915)	53,830	(10,959)
Deferred revenue and customer advances	(7,212)	(14,874)	46,997
Other liabilities	9,666	(529)	2,200
Net cash provided by (used in) operating activities	65,136	(479)	102,783
Investing Activities:
Capital expenditures	(59,815)	(83,702)	(45,343)
Acquisition of business	0	(55,000)	0
Net proceeds from sales of investments	0	4,250	1,138
Net proceeds from sales of property	0	0	100
Net cash used in investing activities	(59,815)	(134,452)	(44,105)
Financing Activities:
Net proceeds from issuance of common stock	2,890	12,126	2,480
Repurchase and retirement of common stock	0	0	(16,681)
Tax benefit of stock-based compensation	1,677	2,234	202
Debt issuance costs	(3,084)	0	0
Net cash provided by (used in) financing activities	1,483	14,360	(13,999)
Net increase (decrease) in cash and cash equivalents	6,804	(120,571)	44,679
Cash and cash equivalents, beginning of year	252,415	372,986	328,307
Cash and cash equivalents, end of year	$ 259,219	$ 252,415	$ 372,986