Stockholders' Equity (Details) - Common Stock - $ / shares			6 Months Ended
May 16, 2019	Mar. 07, 2019	Jun. 30, 2019
Stockholders' Equity
Dividends Payable, Date of Record	Jun. 28, 2019	Mar. 29, 2019
Common Stock dividend declared (per share)	$ 1.22	$ 1.10	$ 2.32

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