Summary of Significant Accounting Policies - Share Based Compensation and Accounting for Income Taxes (Details) - $ / shares	12 Months Ended
Dec. 31, 2019	Dec. 31, 2015	Dec. 31, 2018
Percentage increments vested on anniversaries on the grant date	25.00%	33.33%
Vesting period	4 years
Par value, common stock	$ 0.01		$ 0.01
Cash Settled RSU Plan
Percentage increments vested on anniversaries on the grant date	25.00%
Vesting period	4 years
Number of share of par value $0.01 on which lump sum cash payment is received by RSU holders	1
Par value, common stock	$ 0.01

Face amount or stated value per share of common stock.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(29))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901

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Percentage of vesting of award under share-based payment arrangement.

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Represents the number of share of par value $0.01 on which lump sum cash payment is received by RSU holders.

+ References

No definition available.

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