Equity - AOCI Rollforward (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2019
Changes in the balances of each component of AOCI
Balance at the beginning of the period	$ 411,026	$ 437,775
Total other comprehensive income (loss), net of tax	(42)	16
Balance at the end of the period	402,470	402,470
Accumulated Other Comprehensive Income
Changes in the balances of each component of AOCI
Balance at the beginning of the period	1,878	1,820
Total other comprehensive income (loss), net of tax		16
Balance at the end of the period	1,836	1,836
Foreign Currency Translation
Changes in the balances of each component of AOCI
Balance at the beginning of the period		1,836
Total other comprehensive income (loss), net of tax		8
Balance at the end of the period	1,844	1,844
Unrealized Gains (Losses) on Available for Sale Securities
Changes in the balances of each component of AOCI
Balance at the beginning of the period		(16)
Total other comprehensive income (loss), net of tax		8
Balance at the end of the period	$ (8)	$ (8)

Total of all stockholders' equity (deficit) items, net of receivables from officers, directors, owners, and affiliates of the entity which are attributable to the parent. The amount of the economic entity's stockholders' equity attributable to the parent excludes the amount of stockholders' equity which is allocable to that ownership interest in subsidiary equity which is not attributable to the parent (noncontrolling interest, minority interest). This excludes temporary equity and is sometimes called permanent equity.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 4.E)
-URI http://asc.fasb.org/extlink&oid=27010918&loc=d3e74512-122707

Reference 2: 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(31))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 3: 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

Reference 4: 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(30))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant