Stock-Based Compensation - Summary of Information Regarding Options Outstanding and Exercisable (Detail) (USD $) | 6 Months Ended |
Jun. 30, 2014 |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Options Outstanding, Shares | 4,364,247 |
Options Outstanding, Weighted Average Remaining Contractual Life | '4 years 7 months 6 days |
Options Outstanding, Weighted Average Exercise Price | $3.44 |
Options Exercisable, Shares | 2,993,551 |
Options Exercisable, Weighted Average Exercise Price | $4.19 |
$0.00 - $2.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $0 |
Exercise Prices, Maximum | $2 |
Options Outstanding, Shares | 1,623,752 |
Options Outstanding, Weighted Average Remaining Contractual Life | '6 years 2 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $1.68 |
Options Exercisable, Shares | 427,251 |
Options Exercisable, Weighted Average Exercise Price | $1.58 |
$2.01 - $3.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $2.01 |
Exercise Prices, Maximum | $3 |
Options Outstanding, Shares | 821,390 |
Options Outstanding, Weighted Average Remaining Contractual Life | '4 years 2 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $2.37 |
Options Exercisable, Shares | 648,446 |
Options Exercisable, Weighted Average Exercise Price | $2.37 |
$3.01 - $4.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $3.01 |
Exercise Prices, Maximum | $4 |
Options Outstanding, Shares | 534,429 |
Options Outstanding, Weighted Average Remaining Contractual Life | '3 years 2 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $3.49 |
Options Exercisable, Shares | 533,178 |
Options Exercisable, Weighted Average Exercise Price | $3.49 |
$4.01 - $5.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $4.01 |
Exercise Prices, Maximum | $5 |
Options Outstanding, Shares | 598,444 |
Options Outstanding, Weighted Average Remaining Contractual Life | '3 years 7 months 6 days |
Options Outstanding, Weighted Average Exercise Price | $4.69 |
Options Exercisable, Shares | 598,444 |
Options Exercisable, Weighted Average Exercise Price | $4.69 |
$5.01 - $6.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $5.01 |
Exercise Prices, Maximum | $6 |
Options Outstanding, Shares | 164,524 |
Options Outstanding, Weighted Average Remaining Contractual Life | '3 years 7 months 6 days |
Options Outstanding, Weighted Average Exercise Price | $5.59 |
Options Exercisable, Shares | 164,524 |
Options Exercisable, Weighted Average Exercise Price | $5.59 |
$6.01 - $7.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $6.01 |
Exercise Prices, Maximum | $7 |
Options Outstanding, Shares | 416,032 |
Options Outstanding, Weighted Average Remaining Contractual Life | '4 years 2 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $6.18 |
Options Exercisable, Shares | 416,032 |
Options Exercisable, Weighted Average Exercise Price | $6.18 |
$7.01 - $8.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $7.01 |
Exercise Prices, Maximum | $8 |
Options Outstanding, Shares | 70,000 |
Options Outstanding, Weighted Average Remaining Contractual Life | '1 year 8 months 12 days |
Options Outstanding, Weighted Average Exercise Price | $7.18 |
Options Exercisable, Shares | 70,000 |
Options Exercisable, Weighted Average Exercise Price | $7.18 |
$8.01 - $9.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $8.01 |
Exercise Prices, Maximum | $9 |
Options Outstanding, Shares | 55,000 |
Options Outstanding, Weighted Average Remaining Contractual Life | '10 months 24 days |
Options Outstanding, Weighted Average Exercise Price | $8.98 |
Options Exercisable, Shares | 55,000 |
Options Exercisable, Weighted Average Exercise Price | $8.98 |
$9.01 - $10.00 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $9.01 |
Exercise Prices, Maximum | $10 |
Options Outstanding, Shares | 15,000 |
Options Outstanding, Weighted Average Remaining Contractual Life | '10 months 24 days |
Options Outstanding, Weighted Average Exercise Price | $9.90 |
Options Exercisable, Shares | 15,000 |
Options Exercisable, Weighted Average Exercise Price | $9.90 |
$10.01 - $16.59 [Member] | ' |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] | ' |
Exercise Prices, Minimum | $10.01 |
Exercise Prices, Maximum | $16.59 |
Options Outstanding, Shares | 65,676 |
Options Outstanding, Weighted Average Remaining Contractual Life | '6 months |
Options Outstanding, Weighted Average Exercise Price | $15.76 |
Options Exercisable, Shares | 65,676 |
Options Exercisable, Weighted Average Exercise Price | $15.76 |