Shareholders' Equity (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended	12 Months Ended
Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Equity [Abstract]
Dividend paid					$ 34,164us-gaap_PaymentsOfDividendsCommonStock	$ 21,352us-gaap_PaymentsOfDividendsCommonStock	$ 5,338us-gaap_PaymentsOfDividendsCommonStock
Common Stock, Dividends, Per Share, Cash Paid	$ 0.25	$ 0.25	$ 0.25	$ 0.25	$ 0.40	$ 0.25

Amount of cash outflow in the form of ordinary dividends to common shareholders of the parent entity.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585

Name:	us-gaap_PaymentsOfDividendsCommonStock
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration