Employee Benefit Plans - Defined Contribution Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
Compensation and Retirement Disclosure [Abstract]
Defined Contribution Plan, 401(k) Plan, Employer Matching Contribution, Amount	$ 1.1	$ 1.0
Defined Contribution Plan, 401(k) Plan Employer Matching Contribution, Percentage of Employee Contribution	50.00%
Defined Contribution Plan, 401(k) Plan Employer Matching Contribution, Percent of Employees' Gross Pay	6.00%
Defined Contribution Plan, 401(k) Plan, Employers Matching Contribution, Annual Vesting Percentage	20.00%
Defined Contribution Plan, 401(k) Plan, Vesting Period	5 years
Defined Contribution Plan, 401(k) Plan, Automatic Vesting Age	65 years
Defined Contribution Plan, Employee Contribution Percentage Vested, Percent	100.00%

Defined Contribution Plan, Automatic Vesting Age

No definition available.

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Defined Contribution Plan, Employee Contribution Percentage Vested, Percent

No definition available.

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Defined Contribution Plan, Employer Matching Contribution, Amount

No definition available.

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Defined Contribution Plan, Employer Matching Contribution, Percentage of Employee Contribution

No definition available.

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Defined Contribution Plan, Vesting Period

No definition available.

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

No definition available.

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Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

No definition available.

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