Commitments And Contingencies (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2012	Mar. 31, 2011
Anticipated expenditures relating to completion of construction type contracts	$ 128.8
Rental expense	0.6	0.7
Minimum annual rental commitments, remainder 2012	1.8
Minimum annual rental commitments, 2013	2.4
Minimum annual rental commitments, 2014	2.2
Minimum annual rental commitments, 2015	1.4
Minimum annual rental commitments, 2016	0.2
Minimum annual rental commitments, thereafter	$ 0.7
Maximum [Member] \| Partnership Interest [Member]
Less than joint venture economic interest noted	100.00%

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within one year of the balance sheet date relating to leases defined as operating.

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For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the fourth year of the balance sheet date relating to leases defined as operating.

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the third year of the balance sheet date relating to leases defined as operating.

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due within the second year of the balance sheet date relating to leases defined as operating.

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- Definition

For leases having an initial or remaining non-cancelable letter-terms in excess of one year, required rental payments due after the fifth year from the balance sheet date on leases defined as operating.

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