Earnings per Share Earnings per share narrative (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Sep. 14, 2017	Apr. 10, 2013
Earnings Per Share Narrative [Abstract]
Preferred shares redeemed					2,000	2,000
Excess of fair value over book value of preferred shares redeemed	$ 2,257	$ 0	$ 2,257	$ 0

The excess of (1) fair value of the consideration transferred to the holders of the preferred stock over (2) the carrying amount of the preferred stock in the registrant's balance sheet, during the accounting period.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 260
-SubTopic 10
-Section S99
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=27010884&loc=d3e42851-122695

Name:	us-gaap_PreferredStockRedemptionPremium
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration