Acquisitions and Investment - Purchase Price Consideration Based on Common Stock, Replacement Options and Reduction in Shares (Detail) (Scient'x [Member], USD $) In Thousands, unless otherwise specified	Mar. 31, 2010	Mar. 26, 2010
Scient'x [Member]
Business Acquisition, Equity Interests Issued or Issuable [Line Items]
Fair value of Alphatec common stock issued upon closing		$ 151,639
Fair value of Scient'x Replacement Options attributable to pre-combination service	1,000	1,040
Payable in exchange for reduction in shares to be paid in cash		1,618
Total purchase price		$ 154,297