Summary of Significant Accounting Pronouncements (Details) (USD $)	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012	Dec. 31, 2011
Significant Accounting Policies [Line Items]
Real estate held for development and sale	$ 11,609,000		$ 12,478,000
Goodwill	53,799,000		53,799,000
Cash and cash equivalents	255,961,000		229,121,000		321,990,000	256,990,000
Capitalized Computer Software, Additions	4,100,000		2,500,000		10,900,000
Restructuring and impairment charges (gains), net	(2,643,000)		52,139,000		(3,728,000)
Change in Loss Assumptions, Potential Effect on Operating Results and Financial Position	1,000,000
Minimum [Member]
Significant Accounting Policies [Line Items]
Workers' Compensation Liability	500,000
Maximum [Member]
Significant Accounting Policies [Line Items]
Workers' Compensation Liability	1,000,000
Software Development [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	3 years
Software Development [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Property, Plant and Equipment, Useful Life	5 years
Consolidated Construction Joint Venture [Member] | Joint Venture Consolidated [Member]
Significant Accounting Policies [Line Items]
Cash and cash equivalents	61,276,000	[1]	38,800,000	[1]
Consolidated Construction Joint Venture [Member] | Joint Venture Consolidated [Member] | Minimum [Member]
Significant Accounting Policies [Line Items]
Contract Value of Active Construction Joint Venture Projects	32,700,000
Consolidated Construction Joint Venture [Member] | Joint Venture Consolidated [Member] | Maximum [Member]
Significant Accounting Policies [Line Items]
Contract Value of Active Construction Joint Venture Projects	364,400,000
Unconsolidated Construction Joint Venture [Member] | Partnership Interest [Member]
Significant Accounting Policies [Line Items]
Contract Value of Active Construction Joint Venture Projects	5,700,000,000
Unconsolidated Construction Joint Venture [Member] | Reporting Entitys Interest in Joint Venture [Member]
Significant Accounting Policies [Line Items]
Contract Value of Active Construction Joint Venture Projects	1,700,000,000
Unconsolidated Construction Joint Venture [Member] | Other Partners Interest in Joint Venture [Member]
Significant Accounting Policies [Line Items]
Contract Value of Active Construction Joint Venture Projects	4,000,000,000
Variable Interest Entity, Primary Beneficiary [Member] | Real Estate Entities [Member] | Joint Venture Consolidated [Member]
Significant Accounting Policies [Line Items]
Real estate held for development and sale	11,600,000		12,500,000
Non-Recourse Debt	6,700,000		8,000,000
Residential real estate [Member] | WASHINGTON | Variable Interest Entity, Primary Beneficiary [Member] | Real Estate Entities [Member] | Joint Venture Consolidated [Member]
Significant Accounting Policies [Line Items]
Real estate held for development and sale	$ 11,600,000		$ 11,600,000

[1] The volume and stage of completion of contracts from our consolidated construction joint ventures may cause fluctuations in cash and cash equivalents as well as billings in excess of costs and costs in excess of billings and estimated earnings between periods.