Equity Method Investments - Activity Related to Equity Method Investments (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Equity Method Investments
Balance at beginning of period			$ 68,029	$ 26,892
Contributions			20,798	28,784
Earnings (loss) on equity method investments	$ 1,648	$ 1,063	4,581	1,819
Balance at end of period	$ 93,408	57,495	$ 93,408	57,495
Constitution
Schedule of Equity Method Investments [Line Items]
Ownership percentage	25.00%		25.00%
Equity Method Investments
Balance at beginning of period			$ 64,269	26,892
Contributions			13,500	26,575
Earnings (loss) on equity method investments			4,608	1,938
Balance at end of period	$ 82,377	55,405	82,377	55,405
Summarized Financial Information
Revenues			0	0
Income (loss) from continuing operations			19,366	9,723
Net income			$ 19,366	9,723
Meade
Schedule of Equity Method Investments [Line Items]
Ownership percentage	20.00%		20.00%
Equity Method Investments
Balance at beginning of period			$ 3,760	0
Contributions			7,298	2,209
Earnings (loss) on equity method investments			(27)	(119)
Balance at end of period	$ 11,031	$ 2,090	$ 11,031	$ 2,090