Equity (Details 8)	12 Months Ended
	Dec. 31, 2012
Liability Award Unit Options [Member]
Summary of performance share activity
Shares Outstanding at January 1,	1,083,370
Granted Shares	440,185
Exercised Shares Under Option	(26,855)
Forfeited Shares	(126,383)
Paid	0
Shares Outstanding at December 31,	1,370,317
Expected to vest at December 31,	1,281,440
Liability Award Unit Options [Member] | Minimum [Member]
Summary of performance share activity
Vesting period	1 year
Liability Award Unit Options [Member] | Maximum [Member]
Summary of performance share activity
Vesting period	3 years
Performance Units [Member]
Summary of performance share activity
Shares Outstanding at January 1,	233,257
Granted Shares	158,724
Exercised Shares Under Option	0
Forfeited Shares	(39,823)
Paid	(46,994)
Shares Outstanding at December 31,	305,164
Expected to vest at December 31,	274,648
Liability Award Restricted Units [Member]
Summary of performance share activity
Shares Outstanding at January 1,	510,681
Granted Shares	395,765
Exercised Shares Under Option	0
Forfeited Shares	(75,930)
Paid	(90,080)
Shares Outstanding at December 31,	740,436
Expected to vest at December 31,	666,392
Vesting period	3 years