Summary of Significant Accounting Policies - Schedule of Cash Flows Impact from ASUs Adoption (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) investing activities	$ 1,246,257	$ (428,973)	$ (1,660,365)
Net increase (decrease) in balance	(54,787)	(270,126)	174,330
Cash, cash equivalents and restricted cash, beginning of year	136,990	407,116	232,786
Cash, cash equivalents and restricted cash, end of year	82,203	136,990	407,116
Balance - continuing operations, end of year	82,203	136,990	401,058
Accounting Standards Update 2016-18
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) investing activities		(428,973)	(1,660,365)
Net increase (decrease) in balance		(270,126)	174,330
Cash, cash equivalents and restricted cash, beginning of year		407,116	232,786
Cash, cash equivalents and restricted cash, end of year			407,116
Balance - continuing operations, end of year		136,990	401,058
Pre Cash Flow ASUs
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Net cash provided by (used in) investing activities		(410,617)	(1,672,005)
Net increase (decrease) in balance		(251,770)	162,690
Cash, cash equivalents and restricted cash, beginning of year	$ 94,730	346,500	183,810
Cash, cash equivalents and restricted cash, end of year		94,730	346,500
Balance - continuing operations, end of year		$ 94,730	$ 340,442