Retirement Plan - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Compensation and Retirement Disclosure [Abstract]
Maximum defined contribution plan employees contributions, percentage	100.00%
Percentage of participant contributions considered for first condition of plan	100.00%
Description of percentage of employees eligible earnings subject to match	The Company matches 100% of the first 3% of employee contributions and 50% of the next 2% of employee contributions.
Percentage of participant salary under first condition of plan	3.00%
Percentage of participant contributions considered for second condition of plan	50.00%
Percentage of participant salary under second condition of plan	2.00%
Employer matching contributions to the plan	$ 2.7	$ 1.9	$ 1.3

Defined Contribution Plan Employer Matching Contribution Description

No definition available.

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- Definition

Percentage employer matches of the employee's percentage contribution matched for first condition of plan.

+ References

No definition available.

+ Details

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- Definition

Percentage employer matches of the employee's percentage contribution matched for second condition of plan.

+ References

No definition available.

+ Details

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan under first condition of plan.

+ References

No definition available.

+ Details

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan under second condition of plan.

+ References

No definition available.

+ Details

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- Details

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- Definition

The amount of the cost recognized during the period for defined contribution plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 715

-SubTopic 70

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6414718&loc=d3e28014-114942

+ Details

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

+ Details

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