Stockholders' Equity (Details) - Common Stock - $ / shares				9 Months Ended
Sep. 04, 2019	May 16, 2019	Mar. 07, 2019	Sep. 30, 2019
Stockholders' Equity
Dividends Payable, Date of Record	Sep. 30, 2019	Jun. 28, 2019	Mar. 29, 2019
Common Stock dividend declared (per share)	$ 1.22	$ 1.22	$ 1.10	$ 3.54

Aggregate dividends declared during the period for each share of common stock outstanding.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.3-04)
-URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770

Name:	us-gaap_CommonStockDividendsPerShareDeclared
Namespace Prefix:	us-gaap_
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration