Balance Sheet Details - Summary of Marketable Securities Available-for-Sale (Detail) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2014	Dec. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	$ 5,358	$ 22,616
Gross Unrealized Gains	0	5
Gross Unrealized Losses	0	0
Estimated Fair Value	5,358	22,621
Short-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	5,097	19,173
Gross Unrealized Gains	0	5
Gross Unrealized Losses	0	0
Estimated Fair Value	5,097	19,178
Long-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Amortized Cost	261	3,443
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	261	3,443
Government Agency Securities [Member] | Short-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	1 or less	1 or less
Amortized Cost	0	2,350
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Estimated Fair Value	0	2,351
Municipal Bonds [Member] | Short-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	1 or less	1 or less
Amortized Cost	980	2,828
Gross Unrealized Gains	0	1
Gross Unrealized Losses	0	0
Estimated Fair Value	980	2,829
Municipal Bonds [Member] | Long-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	1 to 2	1 to 2
Amortized Cost	261	0
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	261	0
Certificates of Deposit [Member] | Short-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	1 or less	1 or less
Amortized Cost	4,117	3,360
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	4,117	3,360
Certificates of Deposit [Member] | Long-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	1 to 2	1 to 2
Amortized Cost	0	1,300
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	0	1,300
Corporate Debentures / Bonds [Member] | Short-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	1 or less	1 or less
Amortized Cost	0	10,635
Gross Unrealized Gains	0	3
Gross Unrealized Losses	0	0
Estimated Fair Value	0	10,638
Corporate Debentures / Bonds [Member] | Long-Term Marketable Securities [Member]
Schedule of Available-for-sale Securities [Line Items]
Maturity in Years	1 to 2	1 to 2
Amortized Cost	0	2,143
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 0	$ 2,143