Stock-Based Compensation - Schedule of Outstanding and Exercisable Options (Detail) (USD $) | 9 Months Ended |
Sep. 30, 2013 |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 3,539,450 |
Options Outstanding, Weighted Average Remaining Contractual Life | '4 years 9 months 18 days |
Options Outstanding, Weighted Average Exercise Price | $4.12 |
Options Exercisable, Shares | 2,781,587 |
Options Exercisable, Weighted Average Exercise Price | $4.55 |
$0.00 - $2.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 327,728 |
Options Outstanding, Weighted Average Remaining Contractual Life | '5 years 4 months 24 days |
Options Outstanding, Weighted Average Exercise Price | $1.62 |
Options Exercisable, Shares | 201,827 |
Options Exercisable, Weighted Average Exercise Price | $1.57 |
Exercise price, minimum | $0 |
Exercise prices, maximum | $2 |
$2.01 - $3.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 1,007,749 |
Options Outstanding, Weighted Average Remaining Contractual Life | '5 years |
Options Outstanding, Weighted Average Exercise Price | $2.36 |
Options Exercisable, Shares | 487,084 |
Options Exercisable, Weighted Average Exercise Price | $2.36 |
Exercise price, minimum | $2.01 |
Exercise prices, maximum | $3 |
$3.01 - $4.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 666,752 |
Options Outstanding, Weighted Average Remaining Contractual Life | '5 years 2 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $3.57 |
Options Exercisable, Shares | 599,996 |
Options Exercisable, Weighted Average Exercise Price | $3.57 |
Exercise price, minimum | $3.01 |
Exercise prices, maximum | $4 |
$4.01 - $5.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 700,527 |
Options Outstanding, Weighted Average Remaining Contractual Life | '4 years 1 month 6 days |
Options Outstanding, Weighted Average Exercise Price | $4.68 |
Options Exercisable, Shares | 684,257 |
Options Exercisable, Weighted Average Exercise Price | $4.68 |
Exercise price, minimum | $4.01 |
Exercise prices, maximum | $5 |
$5.01 - $6.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 164,650 |
Options Outstanding, Weighted Average Remaining Contractual Life | '4 years 6 months |
Options Outstanding, Weighted Average Exercise Price | $5.59 |
Options Exercisable, Shares | 157,649 |
Options Exercisable, Weighted Average Exercise Price | $5.61 |
Exercise price, minimum | $5.01 |
Exercise prices, maximum | $6 |
$6.01 - $7.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 448,868 |
Options Outstanding, Weighted Average Remaining Contractual Life | '5 years 9 months 18 days |
Options Outstanding, Weighted Average Exercise Price | $6.17 |
Options Exercisable, Shares | 427,598 |
Options Exercisable, Weighted Average Exercise Price | $6.18 |
Exercise price, minimum | $6.01 |
Exercise prices, maximum | $7 |
$7.01 - $8.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 80,000 |
Options Outstanding, Weighted Average Remaining Contractual Life | '2 years 3 months 18 days |
Options Outstanding, Weighted Average Exercise Price | $7.18 |
Options Exercisable, Shares | 80,000 |
Options Exercisable, Weighted Average Exercise Price | $7.18 |
Exercise price, minimum | $7.01 |
Exercise prices, maximum | $8 |
$8.01 - $9.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 62,500 |
Options Outstanding, Weighted Average Remaining Contractual Life | '2 years 3 months 18 days |
Options Outstanding, Weighted Average Exercise Price | $8.90 |
Options Exercisable, Shares | 62,500 |
Options Exercisable, Weighted Average Exercise Price | $8.90 |
Exercise price, minimum | $8.01 |
Exercise prices, maximum | $9 |
$9.01 - $10.00 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 15,000 |
Options Outstanding, Weighted Average Remaining Contractual Life | '1 year 8 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $9.90 |
Options Exercisable, Shares | 15,000 |
Options Exercisable, Weighted Average Exercise Price | $9.90 |
Exercise price, minimum | $9.01 |
Exercise prices, maximum | $10 |
$10.01 - $16.59 [Member] | ' |
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items] | ' |
Options Outstanding, Shares | 65,676 |
Options Outstanding, Weighted Average Remaining Contractual Life | '1 year 3 months 18 days |
Options Outstanding, Weighted Average Exercise Price | $15.76 |
Options Exercisable, Shares | 65,676 |
Options Exercisable, Weighted Average Exercise Price | $15.76 |
Exercise price, minimum | $10.01 |
Exercise prices, maximum | $16.59 |