Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2015	Dec. 31, 2014
Preferred stock, shares par value	$ 0.01	$ 0.01
Preferred stock, shares authorized	12,500,000us-gaap_PreferredStockSharesAuthorized	12,500,000us-gaap_PreferredStockSharesAuthorized
Common stock, shares par value	$ 0.06	$ 0.06
Common stock, shares authorized	150,000,000us-gaap_CommonStockSharesAuthorized	150,000,000us-gaap_CommonStockSharesAuthorized
Common stock, shares issued	85,026,000us-gaap_CommonStockSharesIssued	79,213,000us-gaap_CommonStockSharesIssued
Common stock, shares outstanding	85,026,000us-gaap_CommonStockSharesOutstanding	79,213,000us-gaap_CommonStockSharesOutstanding
Treasury stock, shares	3,197,000us-gaap_TreasuryStockShares	3,344,000us-gaap_TreasuryStockShares
Series B [Member]
Liquidation preference, per share	$ 25.00	$ 25.00
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	7,950,000	7,950,000
Preferred stock, shares outstanding	7,950,000	7,950,000

Face amount or stated value per share of common stock.

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