Stock-Based Compensation Plans (Narrative) (Details)	3 Months Ended
Mar. 31, 2017 USD ($) plan shares	Mar. 31, 2016 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation expense for share-based payments \| $	$ 3,484,240	$ 4,022,382
Compensation cost capitalized as part of inventory \| $	$ 226,119	$ 292,187
Employee Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares available for grant (in shares) \| shares	24,000,000
Unrecognized compensation cost \| $	$ 15,329,604
Employee Stock Option Plan [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period	1 year
Option expiration period	5 years
Employee Stock Option Plan [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period	5 years
Option expiration period	7 years
Non-Employee Director Stock Option Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Option vesting period	6 months
Option expiration period	10 years
Number of shares authorized (in shares) \| shares	1,000,000
Unrecognized compensation cost \| $	$ 0
Options granted (in shares) \| shares	371,000
Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares approved (in shares) \| shares	2,000,000
ESPP discount rate	85.00%
Shares granted (in shares) \| shares	659,810
ESPP discount rate recognized as compensation expense	15.00%
Restricted Stock Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares) \| shares	9,000,000
Restricted period, maximum, in years	10 years
Unearned stock-based compensation \| $	$ 14,924,917
Amortization expense \| $	$ 940,811
Equity Incentive Plans [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans (in plans) \| plan	4
Stock Options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of plans (in plans) \| plan	2

Share-based compensation arrangement by share-based payment award discount recognized as compensation expense.

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Share-based compensation, restricted period.

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Share-based Compensation Arrangement by Share-based Payment Award, Number of Plans

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- Definition

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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-Publisher FASB
-Name Accounting Standards Codification
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Value of stock issued under share-based plans to employees or officers which is the unearned portion, accounted for under the fair value method.

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Unrecognized cost of unvested share-based compensation awards.

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- Definition

The shares or units in an ESOP trust that have been assigned to individual participant accounts based on a known formula. IRS rules require allocations to be nondiscriminatory generally based on compensation, length of service, or a combination of both. For any particular participant such shares or units may be vested, unvested, or partially vested.

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Sum of the allocated, committed-to-be-released and suspense shares of the entity held by the plan.

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The noncash expense that represents the cost of restricted stock or unit distributed to employees as compensation.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Discount rate from fair value on purchase date that participants pay for shares.

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Gross number of share options (or share units) granted during the period.

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The amount by which an asset or assets increased resulting from the transaction in which equity securities were issued to pay for goods or nonemployee services.

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Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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