Stockholders' Equity (Stock Options Granted) (Details) (USD $)	92 Months Ended	12 Months Ended
Dec. 31, 2014	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted	9,055,000
Options Outstanding	4,712,330	4,712,330
Options Exercisable	1,972,330	1,972,330
April 22, 2014 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		955,000
Option Exercise (Strike) Price		$ 56.00
Closing Stock Price on Date of Grant	50.53	$ 50.53
Options Outstanding	852,500	852,500
Options Exercisable	0	0
April 16, 2013 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		205,000
Option Exercise (Strike) Price		$ 54.00
Closing Stock Price on Date of Grant	49.25	$ 49.25
Options Outstanding	155,000	155,000
Options Exercisable	0	0
April 17, 2012 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		1,235,000
Option Exercise (Strike) Price		$ 54.00
Closing Stock Price on Date of Grant	49.01	$ 49.01
Options Outstanding	1,077,500	1,077,500
Options Exercisable	243,750	243,750
April 19, 2011 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		410,000
Option Exercise (Strike) Price		$ 35.00
Closing Stock Price on Date of Grant	31.78	$ 31.78
Options Outstanding	320,000	320,000
Options Exercisable	60,000	60,000
April 20, 2010 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		530,000
Option Exercise (Strike) Price		$ 30.00
Closing Stock Price on Date of Grant	27.13	$ 27.13
Options Outstanding	237,300	237,300
Options Exercisable	102,300	102,300
April 21, 2009 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		790,000
Option Exercise (Strike) Price		$ 27.00
Closing Stock Price on Date of Grant	17.61	$ 17.61
Options Outstanding	345,600	345,600
Options Exercisable	199,350	199,350
April 15, 2008 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		550,000
Option Exercise (Strike) Price		$ 27.00
Closing Stock Price on Date of Grant	24.35	$ 24.35
Options Outstanding	172,500	172,500
Options Exercisable	117,500	117,500
April 17, 2007 [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options Granted		4,380,000
Option Exercise (Strike) Price		$ 22.50
Closing Stock Price on Date of Grant	20.15	$ 20.15
Options Outstanding	1,551,930	1,551,930
Options Exercisable	1,249,430	1,249,430

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Net number of share options (or share units) granted during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)(iv)(1)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

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-Paragraph 2

-Subparagraph (c)(1)(i)-(ii)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

+ References

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