Stockholders' Equity - Treasury Stock (Details) - USD ($) $ in Thousands	12 Months Ended	13 Months Ended
Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2018	Dec. 11, 2017
Treasury Stock
Authorized amount of common stock repurchase (in dollars)				$ 100,000
Purchase of common stock	$ 11,309	$ 3,018	$ 14,300

Equity impact of the cost of common and preferred stock that were repurchased during the period. Recorded using the cost method.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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-Name Accounting Standards Codification
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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Balance Type:	debit
Period Type:	duration