Equity Incentive Plans (Compensation Expense) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Recognized compensation expenses
Stock Option Plan Expense	$ 1,161us-gaap_StockOptionPlanExpense	$ 1,307us-gaap_StockOptionPlanExpense	$ 2,539us-gaap_StockOptionPlanExpense
Restricted Stock Expense	$ 7,748us-gaap_RestrictedStockExpense	$ 6,582us-gaap_RestrictedStockExpense	$ 4,449us-gaap_RestrictedStockExpense

The noncash expense that represents the cost of restricted stock or unit distributed to employees as compensation.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585

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