Quarterly Financial Information Quarterly Financial Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended																12 Months Ended
	Dec. 31, 2013		Sep. 30, 2013		Jun. 30, 2013		Mar. 31, 2013		Dec. 31, 2012		Sep. 30, 2012		Jun. 30, 2012		Mar. 31, 2012		Dec. 31, 2013		Dec. 31, 2012		Dec. 31, 2011
Revenues	$ 136,226	[1]	$ 95,255	[1]	$ 54,945	[1]	$ 42,897	[1]	$ 30,488	[2]	$ 18,945	[2]	$ 11,534	[2]	$ 6,240	[2]	$ 329,323	[3]	$ 67,207	[3]	$ 3,970
Net loss from continuing operations attributable to stockholders	(197,829)	[1]	(80,170)	[1]	(69,603)	[1]	(143,864)	[1]	(16,459)	[2]	(12,768)	[2]	(7,012)	[2]	(4,722)	[2]	(507,781)	[3]	(41,492)	[3]	(3,952)
Net loss from discontinued operations attributable to stockholders	14	[1]	(31)	[1]	0	[1]	(16)	[1]	(251)	[2]	(41)	[2]	(77)	[2]	(322)	[2]	(34)	[3]	(745)	[3]	(852)
Net loss attributable to Stockholders	(197,815)	[1]	(80,201)	[1]	(69,603)	[1]	(143,880)	[1]	(16,710)	[2]	(12,809)	[2]	(7,089)	[2]	(5,044)	[2]	(507,815)	[3]	(42,237)	[3]	(4,804)
Less: dividends declared on preferred shares and RSUs	(3,006)	[1]	(199)	[1]	(233)	[1]	(193)	[1]	(158)	[2]	(140)	[2]	(70)	[2]	0	[2]	(3,631)		(368)		0
Net loss attributable to the common stockholders	(200,821)	[1]	(80,400)	[1]	(69,836)	[1]	(144,073)	[1]	(16,868)	[2]	(12,949)	[2]	(7,159)	[2]	(5,044)	[2]	(507,815)	[3],[4],[5]	(42,237)	[3]	(4,804)
Weighted-average shares outstanding	231,969,433	[1]	221,707,920	[1]	198,956,355	[1]	167,847,516	[1]	180,931,150	[2]	138,348,622	[2]	68,317,195	[2]	23,614,122	[2]	205,341,431	[6]	103,306,366	[6]	3,720,351	[6]
Basic and diluted loss per share from continuing operations attributable to common stockholders	$ (0.87)	[1],[7]	$ (0.36)	[1],[7]	$ (0.35)	[1],[7]	$ (0.86)	[1],[7]	$ (0.09)	[2]	$ (0.09)	[2]	$ (0.10)	[2]	$ (0.20)	[2]	$ (2.41)	[3]	$ (0.40)	[3]	$ (1.04)
Basic and diluted loss per share from discontinued operations attributable to common stockholders	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0.00	[2]	$ 0.00	[2]	$ 0.00	[2]	$ (0.01)	[2]	$ 0
Basic and diluted net loss per share attributable to common stockholders	$ (0.87)	[1]	$ (0.36)	[1]	$ (0.35)	[1]	$ (0.86)	[1]	$ (0.09)	[2]	$ (0.09)	[2]	$ (0.10)	[2]	$ (0.21)	[2]	$ (2.41)	[3]	$ (0.41)	[3]	$ (1.26)
Total quarterly basic and diluted earnings per share, rounding increase (decrease)																	$ 0.03		$ 0.07
Adjustment [Member]
Net loss attributable to Stockholders					(69,604)
As Previously Reported [Member]
Revenues	136,781	[1]	95,255	[1]	54,945	[1]	42,897	[8]	30,488	[8]							329,878	[9]
Net loss from continuing operations attributable to stockholders	(178,800)	[1]	(82,768)	[1]	(71,992)	[1]	(141,161)	[8]	(16,735)	[8]							(480,436)	[9]	(41,492)	[8]
Net loss from discontinued operations attributable to stockholders	(142)	[1]	91	[1]	34	[1]	(2)	[8]	(259)	[8]							(20)	[9]	(745)	[8]
Net loss attributable to Stockholders	(178,942)	[1]	(82,677)	[1]	(71,958)	[1]	(141,163)	[8]	(16,994)	[8]							(480,456)	[9]	(42,237)	[8]
Less: dividends declared on preferred shares and RSUs	(3,006)	[1]	(199)	[1]	(233)	[1]	(193)	[8]	(158)	[8]
Net loss attributable to the common stockholders	(181,948)	[1]	(82,876)	[1]	(72,191)	[1]	(141,356)	[8]	(17,152)	[8]							(480,456)	[4],[5],[9]
Weighted-average shares outstanding	231,969,433	[1]	221,707,934	[1]	198,956,355	[1]	167,847,516	[8]	180,931,150	[8]
Basic and diluted loss per share from continuing operations attributable to common stockholders	$ (0.77)	[1]	$ (0.37)	[1]	$ (0.36)	[1]	$ (0.84)	[8]	$ (0.09)	[8]							$ (2.33)	[9]
Basic and diluted loss per share from discontinued operations attributable to common stockholders	$ 0	[1]	$ 0	[1]	$ 0	[1]	$ 0	[8]	$ 0.00	[8]							$ 0	[9]
Basic and diluted net loss per share attributable to common stockholders	$ (0.78)	[1]	$ (0.37)	[1]	$ (0.36)	[1]	$ (0.84)	[8]	$ (0.09)	[8]							$ (2.33)	[9]
Error Corrections [Member]
Revenues	(555)		0	[10]	0	[11]	0	[11]	0	[12]							(555)
Net loss from continuing operations attributable to stockholders	(19,029)		2,598	[10]	2,389	[11]	(2,703)	[11]	276	[12]							(27,345)		0
Net loss from discontinued operations attributable to stockholders	156		(122)	[10]	(34)	[11]	(14)	[11]	8	[12]							(14)		0
Net loss attributable to Stockholders	(18,873)		2,476	[10]	2,355	[11]	(2,717)	[11]	284	[12]							(27,359)		0
Less: dividends declared on preferred shares and RSUs	0		0	[10]	0	[11]	0	[11]	0	[12]
Net loss attributable to the common stockholders	$ (18,873)		$ 2,476	[10]	$ 2,355	[11]	$ (2,717)	[11]	$ 284	[12]							$ (27,359)	[4],[5]
Weighted-average shares outstanding	0		(14)	[10]	0	[11]	0	[11]	0	[12]
Basic and diluted loss per share from continuing operations attributable to common stockholders	$ (0.10)		$ 0.01	[10]	$ 0.01	[11]	$ (0.02)	[11]	$ 0.00	[12]							$ (0.08)
Basic and diluted loss per share from discontinued operations attributable to common stockholders	$ 0		$ 0	[10]	$ 0	[11]	$ 0	[11]	$ 0.00	[12]							$ 0
Basic and diluted net loss per share attributable to common stockholders	$ (0.09)		$ 0.01	[10]	$ 0.01	[11]	$ (0.02)	[11]	$ 0.00	[12]							$ (0.08)

[1] The historical financial statements have been adjusted for discontinued operations and figures have been recast in applying the carryover basis of accounting to include the effects of the merger with ARCT IV.

[2] Certain historical balances have been restated for discontinued operations.

[3] For discussion on the restatement adjustments, see Note 2 - Restatement of Previously Issued Financial Statements.

[4] The statement of comprehensive loss was originally included within the consolidated statement of operations in the recasted filing, which applied the carryover basis of accounting to include the effects of the merger with ARCT IV; it is now presented as a standalone financial statement.

[5] The statement of comprehensive loss previously began with net loss attributable to common stockholders . The statement has been updated to begin with net loss to properly show the total comprehensive loss.

[6] Weighted-average shares for the year ended December 31, 2013 are adjusted as if the acquisition of all outstanding shares of ARCT III common stock for cash in conjunction with the ARCT III Merger had been completed at inception.

[7] For the year ended December 31, 2013, the total quarterly basic and diluted earnings per share were $0.03 lower than the annual basic and diluted earnings per share due to the effects of rounding.

[8] These financial figures have been recast in applying the carryover basis of accounting to include the effects of the merger with ARCT IV.

[9] These financial statements have been recast in applying the carryover basis of accounting to include the effects of the merger with ARCT IV.

[10] See Note 2 - Restatement of Previously Issued Financial Statements in the Company's Quarterly Report on Form 10-Q for the fiscal period ended September 30, 2014 for further discussion on the restatement adjustments.

[11] See Note 2 - Restatement of Previously Issued Financial Statements in the Company's Quarterly Reports on Forms 10-Q/A for the fiscal periods ended March 31, 2014 and June 30, 2014, respectively, for further discussion on the restatement adjustments.

[12] See Note 2 - Restatement of Previously Issued Financial Statements.