CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (UNAUDITED) (USD $) In Thousands, unless otherwise specified	6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012
OPERATING ACTIVITIES:
Net income (loss)	$ (610)	$ 15,207
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	24,025	25,808
Deferred income tax (benefit) provision	(400)	(2,554)
Amortization of debt issuance costs	1,094	1,480
Non-cash interest expense	3,232	6,496
Payment of accreted interest	0	(30,617)
Loss on disposal of property and equipment	1,831	431
Share-based compensation	4,764	4,355
Excess tax benefits from stock-based compensation arrangements	(102)	(418)
Changes in assets and liabilities, net of business acquisitions:
Accounts receivable	(745)	2,252
Inventories	(23,966)	(2,155)
Prepaid expenses and other current assets	(624)	7,664
Other non-current assets	(368)	(876)
Accounts payable, accrued expenses and other current liabilities	2,893	7,378
Deferred revenue	278	(289)
Other non-current liabilities	(538)	432
Net cash provided by operating activities	10,764	34,594
INVESTING ACTIVITIES:
Purchases of property and equipment	(24,475)	(24,642)
Sales of property and equipment	530	0
Cash used in business acquisition, net of cash acquired	(2,830)	(2,867)
Purchases of short-term investments	0	(67,907)
Maturities of short-term investments	0	26,058
Net cash used in investing activities	(26,775)	(69,358)
FINANCING ACTIVITIES:
Borrowings under senior credit facility	20,000	155,000
Repayments under senior credit facility	0	(12,812)
Payment of liability component of convertible notes	0	(134,383)
Payment of debt issuance costs	(1,013)	0
Proceeds from exercised stock options	234	250
Excess tax benefits from stock-based compensation arrangements	102	418
Net cash provided by (used in) financing activities	19,323	8,473
Effect of exchange rate changes on cash and cash equivalents	(1,614)	953
Net change in cash and cash equivalents	1,698	(25,338)
Cash and cash equivalents at beginning of period	96,938	100,808
Cash and cash equivalents at end of period	$ 98,636	$ 75,470