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

Dividends - Additional Information (Details) - $ / shares		3 Months Ended								12 Months Ended
	Feb. 05, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Dividends [Abstract]
Cash dividends declared per common share (in shares)		$ 0.19625	$ 0.19500	$ 0.19375	$ 0.19250	$ 0.19125	$ 0.19000	$ 0.18875	$ 0.18750	$ 0.77750	$ 0.75750	$ 0.73750
Subsequent Event
Dividends [Abstract]
Cash dividends declared per common share (in shares)	$ 0.19625