Investments in Affiliates Equity Method Investment Summarized Balance Sheet Information (Details) (Other Affiliates [Member], Joint Venture Unconsolidated [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2014		Dec. 31, 2013
Other Affiliates [Member] | Joint Venture Unconsolidated [Member]
Investments in and Advances to Affiliates [Line Items]
Equity Method Investment, Summarized Financial Information, Current Assets	$ 28,891		$ 25,807
Equity Method Investment, Summarized Financial Information, Noncurrent Assets	141,283		148,181
Total assets	170,174		173,988
Equity Method Investment, Summarized Financial Information, Current Liabilities	5,827		6,000
Equity Method Investment, Summarized Financial Information, Noncurrent Liabilities	66,708	[1]	68,544	[1]
Equity Method Investment, Summarized Financial Information, Liabilities	72,535		74,544
Net assets	97,639		99,444
Granite’s share of net assets	$ 32,361		$ 32,480

[1] The balance primarily relates to debt associated with our real estate investments. See Note 12 for further discussion.