Basic and Diluted Net Income (Loss) Per Common Share - Computation of Net Income (Loss) Per Common Share Basic and Diluted (Detail) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended
Dec. 27, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Dec. 28, 2013	Sep. 28, 2013	Jun. 29, 2013	Mar. 30, 2013	Dec. 27, 2014	Dec. 28, 2013	Dec. 29, 2012
Disclosure Basic And Diluted Net Loss Per Common Share Computation Of Net Loss Per Common Share Basic And Diluted [Abstract]
Net income (loss)	$ 8,410us-gaap_NetIncomeLoss	$ 4,843us-gaap_NetIncomeLoss	$ 4,780us-gaap_NetIncomeLoss	$ (4,374)us-gaap_NetIncomeLoss	$ (10,178)us-gaap_NetIncomeLoss	$ 3,347us-gaap_NetIncomeLoss	$ (10,009)us-gaap_NetIncomeLoss	$ (15,279)us-gaap_NetIncomeLoss	$ 13,659us-gaap_NetIncomeLoss	$ (32,119)us-gaap_NetIncomeLoss	$ (85,330)us-gaap_NetIncomeLoss
Basic weighted average common shares outstanding									123,672	117,425	110,739
Employee equity plans (in shares)									4,778	0	0
Assumed conversion of convertible senior notes from conversion spread (in shares)									115	0	0
Dilutive weighted average common shares outstanding									128,565	117,425	110,739
Basic (in usd per share)	$ 0.07us-gaap_EarningsPerShareBasic	$ 0.04us-gaap_EarningsPerShareBasic	$ 0.04us-gaap_EarningsPerShareBasic	$ (0.04)us-gaap_EarningsPerShareBasic	$ (0.08)us-gaap_EarningsPerShareBasic	$ 0.03us-gaap_EarningsPerShareBasic	$ (0.09)us-gaap_EarningsPerShareBasic	$ (0.13)us-gaap_EarningsPerShareBasic	$ 0.11us-gaap_EarningsPerShareBasic	$ (0.27)us-gaap_EarningsPerShareBasic	$ (0.77)us-gaap_EarningsPerShareBasic
Diluted (in usd per share)	$ 0.06us-gaap_EarningsPerShareDiluted	$ 0.04us-gaap_EarningsPerShareDiluted	$ 0.04us-gaap_EarningsPerShareDiluted	$ (0.04)us-gaap_EarningsPerShareDiluted	$ (0.08)us-gaap_EarningsPerShareDiluted	$ 0.03us-gaap_EarningsPerShareDiluted	$ (0.09)us-gaap_EarningsPerShareDiluted	$ (0.13)us-gaap_EarningsPerShareDiluted	$ 0.11us-gaap_EarningsPerShareDiluted	$ (0.27)us-gaap_EarningsPerShareDiluted	$ (0.77)us-gaap_EarningsPerShareDiluted

Basic and Diluted Net Income (Loss) Per Common Share - Computation of Net Income (Loss) Per Common Share Basic and Diluted (Detail) (USD $)
In Thousands, except Per Share data, unless otherwise specified

3 Months Ended

12 Months Ended

Dec. 27, 2014

Sep. 27, 2014

Jun. 28, 2014

Mar. 29, 2014

Dec. 28, 2013

Sep. 28, 2013

Jun. 29, 2013

Mar. 30, 2013

Dec. 27, 2014

Dec. 28, 2013

Dec. 29, 2012

Disclosure Basic And Diluted Net Loss Per Common Share Computation Of Net Loss Per Common Share Basic And Diluted [Abstract]

Net income (loss)

$ 8,410us-gaap_NetIncomeLoss

$ 4,843us-gaap_NetIncomeLoss

$ 4,780us-gaap_NetIncomeLoss

$ (4,374)us-gaap_NetIncomeLoss

$ (10,178)us-gaap_NetIncomeLoss

$ 3,347us-gaap_NetIncomeLoss

$ (10,009)us-gaap_NetIncomeLoss

$ (15,279)us-gaap_NetIncomeLoss

$ 13,659us-gaap_NetIncomeLoss

$ (32,119)us-gaap_NetIncomeLoss

$ (85,330)us-gaap_NetIncomeLoss

Basic weighted average common shares outstanding

123,672us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

117,425us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

110,739us-gaap_WeightedAverageNumberOfSharesOutstandingBasic

Employee equity plans (in shares)

4,778us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment

0us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustment

Assumed conversion of convertible senior notes from conversion spread (in shares)

115us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities

0us-gaap_IncrementalCommonSharesAttributableToConversionOfDebtSecurities

Dilutive weighted average common shares outstanding

128,565us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

117,425us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

110,739us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding

Basic (in usd per share)

$ 0.07us-gaap_EarningsPerShareBasic

$ 0.04us-gaap_EarningsPerShareBasic

$ (0.04)us-gaap_EarningsPerShareBasic

$ (0.08)us-gaap_EarningsPerShareBasic

$ 0.03us-gaap_EarningsPerShareBasic

$ (0.09)us-gaap_EarningsPerShareBasic

$ (0.13)us-gaap_EarningsPerShareBasic

$ 0.11us-gaap_EarningsPerShareBasic

$ (0.27)us-gaap_EarningsPerShareBasic

$ (0.77)us-gaap_EarningsPerShareBasic

Diluted (in usd per share)

$ 0.06us-gaap_EarningsPerShareDiluted

$ 0.04us-gaap_EarningsPerShareDiluted

$ (0.04)us-gaap_EarningsPerShareDiluted

$ (0.08)us-gaap_EarningsPerShareDiluted

$ 0.03us-gaap_EarningsPerShareDiluted

$ (0.09)us-gaap_EarningsPerShareDiluted

$ (0.13)us-gaap_EarningsPerShareDiluted

$ 0.11us-gaap_EarningsPerShareDiluted

$ (0.27)us-gaap_EarningsPerShareDiluted

$ (0.77)us-gaap_EarningsPerShareDiluted

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