Accumulated Other Comprehensive Loss (Tables)
 9 Months Ended
Sep. 30, 2017
Equity [Abstract]  
Summary of Accumulated Other Comprehensive Loss
The following tables summarize the changes in the accumulated other comprehensive loss balance, net of tax, by component (in thousands):
 
Foreign Currency
 
Effective Portion of Change in Fair Value of Derivatives
 
Proportionate Share of Equity Investee’s OCI
 
Total
Balances at December 31, 2015
$
(48,285
)
 
$
(13,462
)
 
$
(12,131
)
 
$
(73,878
)
Other comprehensive income (loss) before reclassifications
9,874

 
(30,990
)
 
(11,684
)
 
(32,800
)
Amounts reclassified from accumulated other comprehensive loss
—

 
8,359

 
2,752

 
11,111

Net current period other comprehensive income (loss)
9,874

 
(22,631
)
 
(8,932
)
 
(21,689
)
Balances at September 30, 2016
$
(38,411
)
 
$
(36,093
)
 
$
(21,063
)
 
$
(95,567
)
Less: accumulated other comprehensive loss attributable to noncontrolling interest, September 30, 2016
—

 
(1,418
)
 
—

 
(1,418
)
Accumulated other comprehensive loss attributable to Pattern Energy, September 30, 2016
$
(38,411
)
 
$
(34,675
)
 
$
(21,063
)
 
$
(94,149
)
 
Foreign Currency
 
Effective Portion of Change in Fair Value of Derivatives
 
Proportionate Share of Equity Investee’s OCI
 
Total
Balances at December 31, 2016
$
(43,500
)
 
$
(12,751
)
 
$
(6,498
)
 
$
(62,749
)
Other comprehensive income (loss) before reclassifications
17,979

 
(2,498
)
 
6,546

 
22,027

Amounts reclassified from accumulated other comprehensive loss due to termination of interest rate swaps
—

 
2,207

 
—

 
2,207

Other amounts reclassified from accumulated other comprehensive loss
—

 
7,023

 
6,471

 
13,494

Net current period other comprehensive income
17,979

 
6,732

 
13,017

 
37,728

Balances at September 30, 2017
$
(25,521
)
 
$
(6,019
)
 
$
6,519

 
$
(25,021
)
Less: accumulated other comprehensive loss attributable to noncontrolling interest, September 30, 2017
—

 
(200
)
 
—

 
(200
)
Accumulated other comprehensive loss attributable to Pattern Energy, September 30, 2017
$
(25,521
)
 
$
(5,819
)
 
$
6,519

 
$
(24,821
)